A347762 - OEIS

%I #7 Sep 12 2021 20:35:35

%S 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,

%T 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,

%U 11,5,16,7,13,8,14,6,18,5,16,10,14

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

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

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

%K nonn

%O 0,3

%A _Ilya Gutkovskiy_, Sep 12 2021