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 A225891 #13 Jul 10 2015 11:01:59
%S A225891 1,2,3,4,5,6,7,8,9,10,11,18,13,14,15,16,17,12,19,50,21,22,23,54,25,26,
%T A225891 27,98,29,30,31,32,33,34,35,36,37,38,39,250,41,42,43,242,75,46,47,162,
%U A225891 49,20,51,338,53,24,55,686,57,58,59,150,61,62,147,64,65,66
%N A225891 Numbers obtained by rotating left the indices in the prime signature of n.
%C A225891 Inverse permutation to A105119.
%C A225891 A072774 gives the fixed points.
%C A225891 The first term which is different from A105119 is a(60).
%C A225891 The first term which is different from A069799 is a(90).
%H A225891 Paul Tek, <a href="/A225891/b225891.txt">Table of n, a(n) for n = 1..10000</a>
%e A225891 a(2250) = a(2*3^2*5^3) = 2^2*3^3*5 = 540.
%t A225891 Table[Times @@ ((ar = Transpose[FactorInteger[n]])[[1]]^RotateLeft[ar[[2]]]), {n, 66}] (* _Ivan Neretin_, Jul 09 2015 *)
%o A225891 (PARI) { a(n)=my(f=factor(n),l=#f[,1]);
%o A225891 return(prod(i=1,l,f[i,1]^f[if(i==l,1,i+1),2])) }
%Y A225891 Cf. A105119, A072774, A069799.
%K A225891 nonn
%O A225891 1,2
%A A225891 _Paul Tek_, May 20 2013