A347762 Number of compositions (ordered partitions) of n into at most 2 prime powers (including 1).

1, 1, 2, 3, 4, 5, 5, 5, 6, 7, 7, 7, 8, 7, 7, 6, 8, 7, 9, 7, 10, 8, 7, 5, 10, 7, 9, 9, 10, 7, 12, 7, 14, 10, 13, 8, 14, 5, 11, 8, 12, 7, 12, 7, 12, 10, 11, 5, 16, 7, 15, 8, 12, 5, 17, 6, 14, 8, 11, 5, 16, 7, 13, 8, 14, 6, 18, 5, 16, 10, 14

Offset

0,3

Links

Table of n, a(n) for n=0..70.

Mathematica

Table[Length@Flatten[Permutations/@IntegerPartitions[n, 2, Join[{1}, Select[Range@n, PrimePowerQ]]], 1], {n, 0, 70}] (* Giorgos Kalogeropoulos, Sep 12 2021 *)

Crossrefs

Cf. A000961, A280543, A282062, A347763, A347764.

Sequence in context: A063273 A349481 A200262 * A270432 A007599 A330881

Adjacent sequences: A347759 A347760 A347761 * A347763 A347764 A347765

Keyword

nonn

Author

Ilya Gutkovskiy, Sep 12 2021

Status

approved