OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MAPLE
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
MATHEMATICA
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 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jun 14 2009
EXTENSIONS
Extended by Emeric Deutsch, Jul 11 2009
STATUS
approved