A338937 a(n+1) = A001414(a(n)) + A001414(a(n-1)) with a(0)=1, a(1)=2.
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, 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, 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
Offset: 0
Keywords
Examples
a(5) = A001414(6) + A001414(4) = 5 + 4 = 9.
Programs
-
Maple
spf:= n -> add(t[1]*t[2],t=ifactors(n)[2]): N:= 100: A:= Array(0..N): A[0]:= 1: A[1]:= 2: for n from 2 to N do A[n]:= spf(A[n-1])+spf(A[n-2]) od: seq(A[i],i=0..N);
Formula
a(n) = a(n-5) for n >= 25.
a(n+1) = A001414(a(n)*a(n-1)).
Comments