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%I #8 Sep 16 2015 13:43:06
%S 1,3,9,13,65,71,497,505,514,524,535,547,7111,7125,106875,106891,
%T 1817147,1817165,34526135,34526155,34526176,34526198,34526221,
%U 34526245,34526270,897683020,897683047,897683075,897683104,897683134,897683165,897683197
%N a(1)=1. a(n) = n*a(n-1) if n*a(n-1) has a fewer number of divisors than n+a(n-1) does. a(n) = n+a(n-1) if n*a(n-1) has a greater or equal number of divisors than n+a(n-1) does.
%e a(6)+7 = 71 + 7 = 78. a(6)*7 = 71 * 7 = 497. 78 has 8 divisors. 497 has 4 divisors. Since 497 has fewer divisors than 78, a(7) is therefore 497.
%t a = {1}; For[n=2, n < 40, n++, If[Length[Divisors[n*a[[ -1]]]] < Length[Divisors[n+ a[[ -1]]]], AppendTo[a, n*a[[ -1]]], AppendTo[a,n + a[[ -1]]]]]; a (* _Stefan Steinerberger_, Oct 26 2007 *)
%Y Cf. A134189.
%K nonn
%O 1,2
%A _Leroy Quet_, Oct 12 2007
%E More terms from _Stefan Steinerberger_, Oct 26 2007