A103765 Number of times n can be written as sum of a minimal set of primes.

1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 3, 1, 3, 6, 2, 1, 3, 1, 2, 1, 4, 7, 4, 1, 2, 1, 3, 1, 4, 1, 3, 1, 4, 1, 5, 1, 4, 14, 3, 1, 5, 1, 3, 16, 4, 1, 6, 1, 3, 1, 5, 20, 6, 1, 2, 1, 5, 1, 6, 1, 5, 1, 5, 27, 7, 1, 4, 1, 5, 1, 8, 1, 5, 28, 4, 1, 9, 1, 4, 32, 5, 35, 7, 1, 3, 1, 6, 1, 8, 1

Offset: 2

Author

Reinhard Zumkeller, Mar 29 2005

Keywords

• nonn

Comments

A051034 gives the minimal number of primes needed to sum to n;

a(A000040(n)) = 1; a(2*k) = A002375(k) for k>2.

Examples

			A051034(25) = 2: a(25) = #{2+23}=1;
A051034(26) = 2: a(26) = #{3+23, 7+19, 13+13} = 3;
A051034(27) = 3: a(27) = #{3+5+19, 3+7+17, 3+11+13, 5+5+17,
5+11+11, 7+7+13} = 6;
A051034(28) = 2: a(28) = #{5+23, 11+17} = 2;
A051034(29) = 1: a(29) = #{29} = 1.