This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A225791 #8 May 16 2013 14:51:01 %S A225791 1,9,54,85,853,1162,4209,11566,20060,68048,76221,441294,3007789, %T A225791 4521955,39443840,39755851 %N A225791 Numbers n such that the sum of first n prime powers (A025475) is divisible by n. %C A225791 a(17) > 146306913. There are 146306913 prime powers <= 2^63. - _Donovan Johnson_, May 16 2013 %e A225791 The sum of first 9 prime powers is 1 + 4 + 8 + 9 + 16 + 25 + 27 + 32 + 49 = 171. Because 171 is divisible by 9, the latter is in the sequence. %Y A225791 Cf. A025475, A225792. %K A225791 nonn,more %O A225791 1,2 %A A225791 _Alex Ratushnyak_, May 16 2013 %E A225791 a(13)-a(16) from _Donovan Johnson_, May 16 2013