Intro to Computer programming worked at calculating digits of pi today. The actual algorithms aren’t too bad, but getting more than the standard number of digits from a double is a bit trickier. Here’s a program that calculates pi using: Bailey–Borwein–Plouffe formula Bellard’s formula and Chudnovsky algorithm Holy smokes is Chudnovsky algorithm’s fast! Plouff Bellard Chudnovsky Iteration […]
2^86 is largest known pwr of 2 that does not contain 0.What about other digits?Does each non-zero digit occur inf often among the pwrs of 2? — James Tanton (@jamestanton) March 6, 2013 Interesting. The Intro to Programming Students gave a crack at this one; and after 30 minutes all were close and half had […]
Number theory nugget: 357686312646216567629137 is a prime number which remains prime after removing any number of digits from the left side! — Maths World UK (@MathsWorldUK) March 4, 2013 Otherwise known as left-truncating primes with every suffix prime and no digit are zero. Here is the whole sequence. It was proven that 357686312646216567629137 is the last […]
[edit 8/20/13: New post with more data on the weights of Oreos and Double Stuf Oreos.] [edit 8/21/13: And Part 3.] Are Double Stuf Oreos really double stuffed? Some disagreement here: Chris Danielson in part 1 2 and 3 versus Chris Lusto in part 1 and 2. Enter in the Mega Stuf Oreo. Is the Mega Stuf double stuffed, triple stuffed, more???? […]
