A130331 - OEIS

%I #10 Apr 08 2024 05:05:40

%S 4,4,4,6,4,4,6,6,4,4,4,4,6,6,4,4,4,9,4,4,6,6,4,10,6,4,6,4,4,4,12,4,6,

%T 7,4,6,4,12,4,6,6,4,10,4,12,4,4,4,12,4,6,4,4,4,12,6,6,9,4,12,4,10,4,6,

%U 6,4,4,16,4,4,6,4,12,4,12,4,4,12,4,4,4,15,4,4,6,6,12,6,4,12,4,4,12,4,10,6,4

%N Number of divisors of A123240(n).

%C By definition, each term is in A001690. - _R. J. Mathar_, Jan 15 2008

%H Amiram Eldar, <a href="/A130331/b130331.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A000005(A123240(n)). - _R. J. Mathar_, Jan 15 2008

%t seq[max_] := Module[{d = DivisorSigma[0, Range[max]], dmax, k = 2}, dmax = Max[d]; While[Fibonacci[k] < dmax, k++]; Select[d, !MemberQ[Fibonacci[Range[2, k]], #] &]]; seq[300] (* _Amiram Eldar_, Apr 08 2024 *)

%Y Cf. A000005, A000379, A123240.

%K easy,nonn

%O 1,1

%A _Giovanni Teofilatto_, Aug 07 2007

%E More terms from _R. J. Mathar_, Jan 15 2008