A341484 Number of ways to write n as an ordered sum of 7 nonprime numbers.

1, 0, 0, 7, 0, 7, 21, 7, 49, 42, 63, 154, 119, 259, 357, 420, 707, 861, 1169, 1666, 2072, 2752, 3703, 4557, 5999, 7637, 9422, 12089, 14931, 18354, 22904, 27825, 33866, 41328, 49539, 59753, 71386, 85071, 100800, 119455, 140448, 164794, 193179, 224826, 261464, 303422

Offset

7,4

Links

Table of n, a(n) for n=7..52.

Maple

b:= proc(n, t) option remember;
      `if`(n=0, `if`(t=0, 1, 0), `if`(t<1, 0, add(
      `if`(isprime(j), 0, b(n-j, t-1)), j=1..n)))
    end:
a:= n-> b(n, 7):
seq(a(n), n=7..52);  # Alois P. Heinz, Feb 13 2021

Mathematica

nmax = 52; CoefficientList[Series[Sum[Boole[!PrimeQ[k]] x^k, {k, 1, nmax}]^7, {x, 0, nmax}], x] // Drop[#, 7] &

Crossrefs

Cf. A005171, A018252, A052284, A076608, A340963, A341454, A341466, A341480, A341481, A341482, A341483, A341485, A341486.

Sequence in context: A246918 A055957 A165090 * A117013 A176015 A322910

Adjacent sequences: A341481 A341482 A341483 * A341485 A341486 A341487

Keyword

nonn

Author

Ilya Gutkovskiy, Feb 13 2021

Status

approved