A341459 Number of compositions of n^2 into n prime parts.
1, 0, 1, 4, 22, 241, 2696, 35218, 529888, 8998419, 169486964, 3496417024, 78344008779, 1891733424205, 48923563968087, 1347813311456319, 39371345548420060, 1214570579814316742, 39430967625404799740, 1343040950675651131103, 47862610677098010505554
Offset: 0
Keywords
Examples
a(3) = 4: 333, 225, 252, 522.
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..100
Programs
-
Maple
b:= proc(n, t) option remember; `if`(n=0, `if`(t=0, 1, 0), `if`(t<1, 0, add( `if`(isprime(j), b(n-j, t-1), 0), j=1..n))) end: a:= n-> b(n^2, n): seq(a(n), n=0..22);
-
Mathematica
b[n_, t_] := b[n, t] = If[n == 0, If[t == 0, 1, 0], If[t < 1, 0, Sum[ If[PrimeQ[j], b[n-j, t-1], 0], {j, 1, n}]]]; a[n_] := b[n^2, n]; Table[a[n], {n, 0, 22}] (* Jean-François Alcover, May 02 2022, after Alois P. Heinz *)
Formula
a(n) = A121303(n^2,n).
Comments