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 A134621 #8 May 10 2013 17:32:43 %S A134621 15,28,39,48,51,65,68,76,77,85,87,93,111,119,133,141,143,148,155,161, %T A134621 175,187,189,209,212,215,221,225,235,244,275,287,295,301,315,316,320, %U A134621 323,329,355,393,403,404,411,428,437,447,451,455,481,505,508,515,517 %N A134621 Numbers such that the arithmetic mean of the 4th power of their prime factors (taken with multiplicity) is a prime. %H A134621 Hieronymus Fischer, <a href="/A134621/b134621.txt">Table of n, a(n) for n = 1..10000</a> %e A134621 a(3)=39, since 39=3*13 and (3^4+13^4)/2=14321 which is prime. %Y A134621 Cf. A001597, A025475, A134333, A134344, A134376. %Y A134621 Cf. A134600, A134602, A134605, A134608, A134613, A134617, A134619. %K A134621 nonn %O A134621 1,1 %A A134621 _Hieronymus Fischer_, Nov 11 2007 %E A134621 Minor edits by _Hieronymus Fischer_, May 06 2013