I am specially interested in number theory, in particular very large numbers.
86 Least prime of the form $38^n+31$ dec 7 '13
37 Why do I get one extra wrong solution? jan 19
36 Making 400k random choices from 400k samples seems to always end up with 63% distinct choices, why? jul 21 '14
17 Draw cards repeatedly, until we find the ace of spades. Probability that we draw between 20 and 30 cards? jan 17
15 A prime of the form $38111111\ldots$ jan 2 '14
15 How many matrices with integer eigenvalues are there? jun 28 '14