Image copyright Richard Termine

It's R.I.P. to Jerry Nelson, the puppeteer behind Sesame Street's resident number expert Count von Count. The Count loved all numbers, but 34,969 in particular. Why?

BBC radio's More or Less team was in a state of great excitement.

We were about to interview one of our heroes: Count von Count, Sesame Street's Transylvanian arithmomaniac.

But what do you say to a Muppet?

The makers of Sesame Street, the children's programme which was celebrating its 40th anniversary in December 2009 when the interview was recorded, offered some guidance in the form of an emailed document entitled Interviewing Muppets.

It suggested some appropriate questions: "How do you like living on Sesame Street?", for instance, or "Who is your best friend?"

Media playback is unsupported on your device Media caption Sesame Street's number expert Count von Count talks to More or Less presenter Tim Harford

The guide gently steered us away from some less appropriate lines of questioning, such as "Are Bert and Ernie gay?"

We had no intention of asking the Count to speculate about what Bert and Ernie get up to in the privacy of the bedroom they share.

No, we were happy to stick to the numbers questions.

But when the time came to record our interview we were hit by a disorientating array of technological problems.

Had the producer, Richard Knight, read the guidance document on interviewing Muppets carefully he would have been more prepared for what happened next.

Image copyright Rex Features Image caption One - ah ha ha!

"Muppets", the document read, "always stay in character".

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So that's how Richard found himself discussing ISDN line settings, not with the late Jerry Nelson, the venerable occupant of the Count costume, who died aged 78 on 23 August, but with Count von Count himself - who punctuated Richard's lengthy technical briefing (the problems went on for at least 40 minutes) with cries of "Werry good!", "Yeees" and, of course, "Ah ha ha ha!"

Eventually the interview started. And, as a rigorous current affairs programme, More or Less elicited some revealing information.

What's the first thing the Count counted? His fingers, his toes, his ears and his nose (in that order).

We couldn't shy away from the question of arithmomania, a disorder which involves the obsessive counting of surrounding objects.

The man behind the Count Image copyright AP Jerry Nelson born in Tulsa, Oklahoma, in 1934

Worked with Jim Henson's muppeteers in 1965

Joined Sesame Street in the early 1970s

Also provided voices for woolly mammoth puppet Mr Snuffleupagus and Herry Monster

Reportedly based Count von Count's accent on Dracula actor Bela Lugosi

Involved in other Henson projects such as 1984 film The Muppets Take Manhattan, and TV's Fraggle Rock and Muppets Tonight

Had the love of counting ever caused the Count problems?

"Well, yes, once I tried to count my chickens before they hatched," he said.

"In the end, what I thought were 10 chickens were, in reality, five chickens, three turtles and two alligators. The people who thought they were buying chickens were not amused."

But he laughed off suggestions that, while working as a lift operator, his refusal to let Kermit the Frog out at the floor he wanted had damaged relations between the two.

The Count had insisted they travel the whole length of the building so he could count all the floors.

"It was a minor setback in our relationship," he said.

"I often find this the case - people sometimes do not understand how important counting is.

"But we sorted that out, I think. We are still werry good friends."

Image copyright AP Image caption Count von Count was a sharp dresser, with a style reminiscent of Bela Lugosi

But if nothing fazed the Count, the same could not be said for the More or Less team.

What was the Count's favourite number, they asked, in the programme's trademark penetrating style.

Count-isms Image copyright Getty Images Count von Count loves numbers and is known for responding excitedly to counting sessions: "I am the Count. They call me the Count because I love to count things"

"When I'm alone, I count myself. One count!"

Known to laugh maniacally after each counting session: "AH AH AH!"

"Eight, eight, eight, eight is great. It makes me shout 'hooray'"

"That was splendid, superb! It almost rained! Let's do it again" (On directing Liam Neeson to count to 20)

"I admit it... I'm in love with the number seven. So beautiful, so... seven-y" (to Julianne Moore)

34,969.

The team were stumped.

"It's a square-root thing," the Count added, by way of explanation.

34,969 is 187 squared. But why 187?

More or Less turned to its listeners for help.

Toby Lewis noted that 187 is the total number of points on the tiles of a Scrabble game, speculating that the Count might have counted them.

David Lees noticed that 187 is the product of two primes - 11 and 17 - which makes 34,969 a very fine number indeed, being 11 squared times 17 squared. What, he asked, could be lovelier?

And Simon Philips calculated that 187 is 94 squared minus 93 squared - and of course 187 is also 94 plus 93 (although that would be true of any two consecutive numbers, as reader Lynn Wragg pointed out). An embarrassment of riches!

But both he and Toby Lewis hinted at darkness behind the Count's carefree laughter and charming flashes of lightning: 187 is also the American police code for murder.

Murder squared: was the Count trying to tell us something?

Here is a selection of readers' favourite numbers.