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A344446 Number of partitions of n into 3 semiprimes. 2
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 2, 1, 1, 1, 3, 2, 3, 2, 2, 3, 3, 4, 4, 2, 3, 5, 7, 5, 4, 4, 5, 6, 7, 7, 6, 6, 7, 10, 10, 7, 7, 9, 10, 11, 11, 13, 13, 8, 12, 14, 14, 13, 9, 13, 14, 16, 17, 19, 15, 15, 15, 22, 23, 15, 14, 19, 23, 23, 22, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,19

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..20000

FORMULA

a(n) = [x^n y^3] 1/Product_{j>=1} (1-y*x^A001358(j)).

MAPLE

h:= proc(n) option remember; `if`(n=0, 0,

     `if`(numtheory[bigomega](n)=2, n, h(n-1)))

    end:

b:= proc(n, i) option remember; series(`if`(n=0, 1, `if`(i<1, 0,

     `if`(i>n, 0, x*b(n-i, h(min(n-i, i))))+b(n, h(i-1)))), x, 4)

    end:

a:= n-> coeff(b(n, h(n)), x, 3):

seq(a(n), n=0..80);

CROSSREFS

Column k=3 of A344447.

Cf. A001358.

Sequence in context: A120221 A300655 A290601 * A094899 A057774 A089355

Adjacent sequences:  A344443 A344444 A344445 * A344447 A344448 A344449

KEYWORD

nonn,look

AUTHOR

Alois P. Heinz, May 19 2021

STATUS

approved

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Last modified July 27 15:49 EDT 2021. Contains 346308 sequences. (Running on oeis4.)