A134192 - OEIS

%I #9 Sep 16 2015 13:42:52

%S 1,1,1,1,1,1,2,1,2,2,3,1,5,1,6,8,6,1,14,1,22,20,23,1,43,22,44,43,64,1,

%T 129,1,129,152,130,193,282,1,283,326,476,1,995,1,1147,1471,1148,1,

%U 2619,995,4090,2749,4416,1,7165,5237,8160,7448,8161,1,20846,1,20847,29006

%N a(0) = a(1) = 1. a(n) = Sum_{p|n} a(n-p), where the sum is over all distinct primes p that divide n.

%e The distinct primes that divide 12 are 2 and 3. So a(12) = a(12-2) + a(12-3) = a(10) + a(9) = 3 + 2 = 5.

%t a = {1, 1}; For[n = 2, n < 80, n++, s = 0; For[i = 1, i < Length[Divisors[n]] + 1, i++, If[PrimeQ[Divisors[n][[i]]], s = s + a[[n - Divisors[n][[i]] + 1]]]]; AppendTo[a, s]]; a (* _Stefan Steinerberger_, Aug 30 2008 *)

%K nonn

%O 0,7

%A _Leroy Quet_, Jan 13 2008

%E More terms from _Stefan Steinerberger_, Aug 30 2008