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%I #13 Feb 26 2019 22:45:35
%S 1,4,6,8,9,12,14,16,18,20,21,24,25,28,30,32,33,36,38,40,42,44,45,48,
%T 50,52,54,56,57,60,62,64,66,68,70,72,74,75,76,80,81,84,85,88,90,92,93,
%U 96,98,100,102,104,105,108,110,112,114,116,117,120,121,124,126,128,130,132
%N a(1)=1. a(n) = the smallest integer > a(n-1) such that d(a(n)) > d(n), where d(n) = the number of divisors of n.
%H Harvey P. Dale, <a href="/A161576/b161576.txt">Table of n, a(n) for n = 1..1000</a>
%p with(numtheory): a := proc (n) local j: if n = 1 then 1 else for j from a(n-1)+1 while tau(j) <= tau(n) do end do: j end if end proc: seq(a(n), n = 1 .. 70); # _Emeric Deutsch_, Jul 11 2009
%t si[{n_,a_}]:=Module[{k=a+1,d=DivisorSigma[0,n+1]},While[DivisorSigma[0,k]<=d,k++];{n+1,k}]; NestList[si,{1,1},70][[All,2]] (* _Harvey P. Dale_, Nov 12 2017 *)
%Y Cf. A137518, A161577, A161578.
%K nonn
%O 1,2
%A _Leroy Quet_, Jun 14 2009
%E Extended by _Emeric Deutsch_, Jul 11 2009