A050221 a(n) = number of sets of consecutive primes whose arithmetic mean is A060863(n).

1, 1, 1, 2, 1, 1, 2, 1, 3, 1, 3, 2, 2, 1, 1, 2, 2, 2, 2, 5, 2, 3, 2, 4, 2, 1, 3, 2, 1, 1, 2, 2, 1, 5, 1, 4, 2, 2, 1, 3, 1, 2, 1, 1, 4, 1, 2, 1, 1, 1, 1, 3, 2, 2, 2, 1, 1, 5, 3, 1, 1, 1, 2, 2, 2, 1, 1, 3, 3, 1, 4, 1, 2, 2, 1, 3, 3, 1, 3, 1, 2, 1, 1, 3, 1, 1, 1, 2, 1, 3, 1, 1, 1, 2, 3, 1, 1, 2, 4, 4, 2, 4, 1, 3, 2

Offset: 1

Author

Naohiro Nomoto, May 08 2003

Keywords

• easy
• nonn

Comments

Essentially A122821 with the 0's removed.

Examples

			For n=4; A060863(4) = 5. the two sets are 5/1 = 5, (3+5+7)/3 = 5. so a(4)=2.
		

Crossrefs

Cf. A060863, A122821.

Programs

Mathematica

f[n_]:=Block[{i=1,j,c=0,m},While[Prime[i]<=n, j=1; While[m=Sum[Prime[k],{k,i,i+j-1}]/j; If[m==n,c++ ]; m0&] (* Ray Chandler, Oct 03 2006 *)

Formula

a(n) = A122821(A060863(n)).

Extensions

Extended by Ray Chandler, Oct 03 2006