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 A080613 #3 Mar 30 2012 18:50:31 %S A080613 1,2,3,4,25,6,49,8,27,20,1331,12,2197,28,45,16,83521,36,130321,40,189, %T A080613 88,279841,24,625,104,81,56,707281,60,923521,32,891,272,4375,72, %U A080613 69343957,304,1053,80,115856201,168,147008443,176,405,368,229345007,48 %N A080613 Minimal sequence such that Omega(a(m))<=Omega(a(n)) for m<n, where Omega=A001222 (sum of exponents in prime factorization). %C A080613 a(n)=n iff n=2^k or n=3*2^k (A029744); A001222(a(n))=A000523(n). %F A080613 a(1) = 1, a(n) = if Omega(n)<Omega(a(n-1)) then n*spf(n)^(Omega(a(n-1))-Omega(n)) else n, where spf=A020639 (smallest prime factor). %K A080613 nonn %O A080613 1,2 %A A080613 _Reinhard Zumkeller_, Feb 25 2003