Entries from 2007-01-20 to 1 day
non-decreasing squares have infinite patterns # Knuth's Monotonic Squares # n and n^2 have non-decreasing digits def digit(n, i) (n/10**i)%10 end def nondec?(n) i = n.to_s.length - 1 i == 0 || digit(n, i) <= digit(n, i-1) && nondec?(n%10**…