A068320 - OEIS

%I #2 Mar 31 2012 13:50:43

%S 0,1,1,0,2,0,2,1,1,1,1,1,2,1,2,2,1,2,2,2,2,2,1,3,1,2,0,2,1,3,2,2,3,3,

%T 0,4,1,1,3,3,1,4,2,3,1,3,1,5,1,4,3,3,1,5,1,4,1,3,1,6,2,2,1,5,0,6,1,2,

%U 4,5,1,6,2,4,1,5,0,7,1,5,1,4,1,8,2,4,3,4,1,9,1,5,2,4,0,7,1

%N a(n)=number of arithmetic progressions of primes, strictly increasing with sum n.

%K easy,nonn

%O 1,5

%A _Naohiro Nomoto_, Feb 27 2002