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

2,9

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.

Links

Table of n, a(n) for n=2..103.

Example

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.

Crossrefs

Sequence in context: A317145 A330665 A345985 * A344772 A307610 A125029

Adjacent sequences: A103762 A103763 A103764 * A103766 A103767 A103768

Keyword

nonn

Author

Reinhard Zumkeller, Mar 29 2005

Status

approved