A341451 Number of partitions of n into 4 nonprime parts.

1, 0, 0, 1, 0, 1, 1, 1, 2, 2, 2, 3, 3, 4, 6, 5, 7, 8, 9, 10, 13, 13, 17, 17, 22, 21, 27, 27, 34, 34, 41, 40, 51, 49, 62, 59, 71, 70, 86, 82, 101, 97, 117, 112, 135, 131, 155, 150, 180, 170, 202, 196, 228, 222, 259, 248, 291, 281, 324, 314, 361, 348, 404, 388, 445, 431

Offset

4,9

Links

Table of n, a(n) for n=4..69.

Maple

b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(isprime(i), 0, b(n-i, min(n-i, i), t-1))))
    end:
a:= n-> b(n$2, 4):
seq(a(n), n=4..69);  # Alois P. Heinz, Feb 12 2021

Mathematica

b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[PrimeQ[i], 0, b[n - i, Min[n - i, i], t - 1]]]];
a[n_] := b[n, n, 4];
Table[a[n], {n, 4, 69}] (* Jean-François Alcover, Aug 19 2021, after Alois P. Heinz *)

Crossrefs

Cf. A002095, A005171, A018252, A062610, A259194, A341408, A341452, A341453, A341454, A341455, A341457.

Sequence in context: A054911 A367215 A137267 * A123576 A094824 A029054

Adjacent sequences: A341448 A341449 A341450 * A341452 A341453 A341454

Keyword

nonn

Author

Ilya Gutkovskiy, Feb 12 2021

Status

approved