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 A134612 #15 Nov 04 2013 21:50:10
%S A134612 4,8,9,16,25,27,32,49,64,81,121,125,128,169,243,256,289,343,361,512,
%T A134612 529,625,729,841,961,1024,1331,1369,1681,1849,2048,2187,2197,2209,
%U A134612 2401,2809,3125,3481,3721,4096,4489,4913,5041,5329,6241,6561,6859,6889,7921
%N A134612 Nonprime numbers such that the root mean cube of their prime factors is a prime (where the root mean cube of c and d is ((c^3+d^3)/2)^(1/3)).
%C A134612 The prime factors are taken with multiplicity.
%C A134612 All perfect prime powers (A025475) with power > 1 are included. First term not included in A025475 is a(211) = 707265 = A134614(5) = A134615(1).
%C A134612 Originally, the first term was 1. This was wrong, since the cube mean of the prime factors of 1 is zero, by definition of the empty sum.
%H A134612 Hieronymus Fischer, <a href="/A134612/b134612.txt">Table of n, a(n) for n = 1..8600</a>
%e A134612 a(5) = 25, since 25 = 5*5 and ((5^3+5^3)/2)^(1/3) = 5.
%o A134612 (PARI) lista(m) = {for (i=2, m, if (! isprime(i), f = factor(i); s = sum (j=1, length(f~), f[j,1]^3*f[j,2]); s /= bigomega(i); if (type(s) == "t_INT" && ispower(s, 3, &p) && isprime(p), print1(i, ", "));););} \\ _Michel Marcus_, Apr 14 2013
%Y A134612 Cf. A001597, A025475, A134333, A134344, A134376.
%Y A134612 Cf. A134600, A134602, A134605, A134614, A134617, A134619, A134621.
%K A134612 nonn
%O A134612 1,1
%A A134612 _Hieronymus Fischer_, Nov 11 2007
%E A134612 Edited by _Hieronymus Fischer_, May 30 2013