A095840 Number of ways to write the n-th prime power as sum of two prime powers.

0, 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 3, 3, 2, 3, 4, 3, 3, 7, 2, 3, 3, 2, 3, 2, 2, 3, 7, 2, 2, 3, 2, 4, 4, 3, 2, 2, 2, 2, 2, 4, 2, 3, 1, 11, 3, 3, 4, 0, 2, 3, 1, 3, 3, 3, 1, 4, 1, 1, 2, 4, 2, 1, 3, 3, 2, 1, 3, 5, 1, 12, 3, 2, 1, 3, 2, 2, 3, 2, 4, 2, 1, 2, 2, 0, 1, 1, 3, 2, 4, 2, 3, 2, 0, 2, 3, 1, 2, 2, 2, 1, 3

Offset

1,4

Comments

a(n) = A071330(A000961(n)).

See A095842 and A095841 for prime powers having no more than one partition into two prime powers.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Example

A000961(8) = 3^2 = 9 = 1+8 = 2+7 = 4+5, therefore a(8)=3.

Prog

(Haskell)
a095840 = a071330 . a000961  -- Reinhard Zumkeller, Jan 11 2013

Crossrefs

Sequence in context: A162345 A048689 A069923 * A131343 A089051 A364631

Adjacent sequences: A095837 A095838 A095839 * A095841 A095842 A095843

Keyword

nonn

Author

Reinhard Zumkeller, Jun 10 2004

Status

approved