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A341947
Number of partitions of n into 4 primes (counting 1 as a prime).
12
1, 1, 2, 2, 4, 3, 5, 4, 6, 4, 7, 4, 9, 6, 10, 6, 12, 6, 14, 8, 15, 8, 18, 9, 21, 10, 20, 9, 23, 10, 26, 12, 27, 12, 31, 13, 34, 13, 33, 14, 39, 15, 42, 16, 43, 17, 48, 18, 53, 19, 52, 19, 58, 20, 61, 20, 61, 20, 68, 23, 73, 23, 73, 26, 82, 26, 84, 23, 84, 27, 92, 28, 98
OFFSET
4,3
LINKS
MAPLE
b:= proc(n, i) option remember; series(`if`(n=0, 1,
`if`(i<0, 0, (p-> `if`(p>n, 0, x*b(n-p, i)))(
`if`(i=0, 1, ithprime(i)))+b(n, i-1))), x, 5)
end:
a:= n-> coeff(b(n, numtheory[pi](n)), x, 4):
seq(a(n), n=4..76); # Alois P. Heinz, Feb 24 2021
MATHEMATICA
b[n_, i_] := b[n, i] = Series[If[n == 0, 1,
If[i < 0, 0, Function[p, If[p > n, 0, x*b[n - p, i]]][
If[i == 0, 1, Prime[i]]] + b[n, i - 1]]], {x, 0, 5}];
a[n_] := Coefficient[b[n, PrimePi[n]], x, 4];
Table[a[n], {n, 4, 76}] (* Jean-François Alcover, Feb 15 2022, after Alois P. Heinz *)
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 24 2021
STATUS
approved