A341461 Number of partitions of n into 3 distinct nonprime parts.
1, 0, 1, 1, 2, 1, 2, 2, 4, 3, 4, 4, 6, 5, 8, 7, 9, 9, 10, 12, 14, 14, 14, 17, 19, 19, 22, 23, 24, 28, 27, 31, 33, 35, 36, 40, 40, 44, 47, 49, 50, 55, 53, 61, 62, 66, 65, 73, 72, 79, 81, 86, 85, 95, 91, 101, 101, 109, 107, 119, 114, 125, 125, 134, 134
Offset: 11
Keywords
Links
- Alois P. Heinz, Table of n, a(n) for n = 11..10000
Crossrefs
Programs
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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-1), t-1)))) end: a:= n-> b(n$2, 3): seq(a(n), n=11..75); # Alois P. Heinz, Feb 12 2021
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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 - 1], t - 1]]]]; a[n_] := b[n, n, 3]; a /@ Range[11, 75] (* Jean-François Alcover, Jul 01 2021, after Alois P. Heinz *)
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Python
from functools import lru_cache from sympy import isprime @lru_cache(maxsize=None) def b(n, i, t): if n == 0: return int(t == 0) if i < 1 or t < 1: return 0 b2 = 0 if isprime(i) else b(n-i, min(n-i, i-1), t-1) return b(n, i-1, t) + b2 a = lambda n: b(n, n, 3) print([a(n) for n in range(11, 76)]) # Michael S. Branicky, Feb 12 2021 after Alois P. Heinz