cp's OEIS Frontend

A338937 a(n+1) = A001414(a(n)) + A001414(a(n-1)) with a(0)=1, a(1)=2.

%I A338937 #9 Nov 16 2020 23:33:17
%S A338937 1,2,2,4,6,9,11,17,28,28,22,24,22,22,26,28,26,26,30,25,20,19,28,30,21,
%T A338937 20,19,28,30,21,20,19,28,30,21,20,19,28,30,21,20,19,28,30,21,20,19,28,
%U A338937 30,21,20,19,28,30,21,20,19,28,30,21,20,19,28,30,21,20,19,28,30,21,20,19,28,30,21,20,19
%N A338937 a(n+1) = A001414(a(n)) + A001414(a(n-1)) with a(0)=1, a(1)=2.
%C A338937 Enters 5-cycle 20,19,28,30,21 starting with a(20).
%F A338937 a(n) = a(n-5) for n >= 25.
%F A338937 a(n+1) = A001414(a(n)*a(n-1)).
%e A338937 a(5) = A001414(6) + A001414(4) = 5 + 4 = 9.
%p A338937 spf:= n -> add(t[1]*t[2],t=ifactors(n)[2]):
%p A338937 N:= 100:
%p A338937 A:= Array(0..N): A[0]:= 1: A[1]:= 2:
%p A338937 for n from 2 to N do
%p A338937   A[n]:= spf(A[n-1])+spf(A[n-2])
%p A338937 od:
%p A338937 seq(A[i],i=0..N);
%Y A338937 Cf. A001414, A338938.
%K A338937 nonn
%O A338937 0,2
%A A338937 _J. M. Bergot_ and _Robert Israel_, Nov 16 2020