A062305 Number of ways writing 2^n as a sum of a prime and a nonprime.

0, 0, 1, 2, 2, 7, 8, 25, 38, 75, 128, 259, 458, 876, 1598, 3024, 5672, 10753, 20372, 38656, 73547, 140669, 268537, 514307, 986379, 1896755, 3650109, 7036061, 13580371, 26241380, 50765806, 98317489, 190597373

Offset

0,4

Links

Table of n, a(n) for n=0..32.

Formula

a(n) = A062602(2^n) = number of prime+nonprime partitions of 2^n.

Example

n = 5: 2^5 = 32 = 31+1 = 2+30 = 5+27 = 7+25 = 11+21 = 17+15 = 23+9 so a(5) = 7.

Crossrefs

Cf. A061358, A062602, A062610.

Sequence in context: A019087 A293607 A026563 * A155063 A324666 A011022

Adjacent sequences: A062302 A062303 A062304 * A062306 A062307 A062308

Keyword

nonn

Author

Labos Elemer, Jul 05 2001

Extensions

More terms from Dean Hickerson, Jul 23 2001

a(28)-a(32) from Sean A. Irvine, Mar 25 2023

Status

approved