login
A347741
Number of compositions (ordered partitions) of n into at most 4 prime parts.
6
1, 0, 1, 1, 1, 3, 2, 6, 6, 10, 15, 15, 24, 25, 31, 36, 35, 45, 50, 55, 63, 69, 73, 90, 91, 99, 113, 114, 130, 143, 144, 153, 166, 159, 195, 179, 213, 191, 253, 216, 279, 236, 288, 247, 343, 248, 377, 275, 397, 318, 456, 307, 503, 342, 524, 401, 572, 379, 641, 396, 667
OFFSET
0,6
FORMULA
a(n) = Sum_{k=1..4} A121303(n,k) for n >= 2. - Alois P. Heinz, Sep 11 2021
MATHEMATICA
Table[Length@Flatten[Permutations/@IntegerPartitions[n, 4, Prime@Range@PrimePi@n], 1], {n, 0, 60}] (* Giorgos Kalogeropoulos, Sep 12 2021 *)
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Sep 11 2021
STATUS
approved