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 A086482 #11 Jun 03 2015 17:23:48 %S A086482 1,4,2,32,128,8,1024,16,8192,32768,64,262144,1048576,256,8388608,512, %T A086482 67108864,268435456,2048,2147483648,4096,17179869184,68719476736, %U A086482 16384,549755813888,2199023255552,65536,17592186044416,131072,140737488355328 %N A086482 Beginning with 1, the smallest number not included earlier such that the n-th partial product is an n-th power; or the geometric mean of the first n terms is an integer. %C A086482 Every term is a power of 2 and the geometric mean of first n terms is 2 for n >1. Rearrangement of powers of 2. %F A086482 a(n) = 2^A002251(n-1). - _David Wasserman_, Mar 07 2005 %e A086482 a(5) = 128: the product of the first five terms is 1*4*2*32*128 = 2^15 = 8^5; 4 gives 4^5, also a 5th power, but 4 is already included. %o A086482 (PARI) v=[1];n=1;while(n<10^4,p=n*prod(i=1,#v,v[i]);if(ispower(p,#v+1)&&!vecsearch(vecsort(v),n),v=concat(v,n);n=1);n++);v \\ _Derek Orr_, May 27 2015 %Y A086482 Cf. A002251. %K A086482 nonn %O A086482 1,2 %A A086482 _Amarnath Murthy_, Jul 26 2003 %E A086482 More terms from _David Wasserman_, Mar 07 2005