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Integer sequence review: A051200

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The Online Encyclopedia of Integer Sequences contains over 200,000 sequences. It contains classics, curios, thousands of derivatives entered purely for completeness’s sake, short sequences whose completion would be a huge mathematical achievement, and some entries which are just downright silly.

For a lark, David and I have decided to review some of the Encyclopedia’s sequences. We’ll be rating sequences on four axes: Novelty, Aesthetics, Explicability and Completeness.

A051200
Except for initial term, primes of form “n 3′s followed by 1″.

3, 31, 331, 3331, 33331, 333331, 3333331, 33333331, 333333333333333331, 3333333333333333333333333333333333333331, 33333333333333333333333333333333333333333333333331, ...

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Carnival of Mathematics 98

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The next issue of the Carnival of Mathematics, rounding up blog posts from the month of April, is now online at Andrew Taylor’s blog.

The Carnival rounds up maths blog posts from all over the internet, including some from our own Aperiodical. For more information about the Carnival of Mathematics, click here.

Integer sequence review: A010727

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The Online Encyclopedia of Integer Sequences contains over 200,000 sequences. It contains classics, curios, thousands of derivatives entered purely for completeness’s sake, short sequences whose completion would be a huge mathematical achievement, and some entries which are just downright silly.

For a lark, David and I have decided to review some of the Encyclopedia’s sequences. We’ll be rating sequences on four axes: Novelty, Aesthetics, Explicability and Completeness.

A010727
Constant sequence: the all 7′s sequence.

7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, ...

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Monthly MathsJams – November 2012 Survey Data

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Those of you with long, long memories (and who attend a MathsJam) may recall that back in November 2012, MathsJam HQ sent out a questionnaire to monthly regional meetups, with various questions about attendance and ping-pong balls. The purpose of the survey was to get a snapshot of what the monthly MathsJams are like, as well as to produce some spurious graphs. Christian and I, who run the Newcastle and Manchester MathsJams respectively, were tasked with analysing the data. Here are our findings!

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