Dear seqfans, A064539= (*Numbers n such that 2^n+n^2 is prime*){1,3,9,15,21,33,2007,2127,3759,29355,34653,57285,99069}All except first are divisible by 3 but why? zak __________________________________ Do you Yahoo!? Make Yahoo! your home page http://www.yahoo.com/r/hs