A321775 Number of compositions of n into parts with distinct multiplicities and with exactly five parts.

1, 5, 15, 15, 20, 6, 30, 20, 35, 35, 21, 35, 50, 40, 50, 36, 55, 55, 65, 55, 56, 70, 70, 70, 85, 61, 85, 85, 90, 90, 86, 90, 105, 105, 105, 91, 120, 110, 120, 120, 111, 125, 135, 125, 140, 126, 140, 140, 155, 145, 141, 155, 160, 160, 170, 146, 175, 175, 175

Offset

5,2

Links

Alois P. Heinz, Table of n, a(n) for n = 5..1000

Formula

Conjectures from Colin Barker, Dec 11 2018: (Start)

G.f.: x^5*(1 + 6*x + 21*x^2 + 35*x^3 + 49*x^4 + 34*x^5 + 29*x^6) / ((1 - x)^2*(1 + x)*(1 + x^2)*(1 + x + x^2)*(1 + x + x^2 + x^3 + x^4)).

a(n) = -a(n-1) - a(n-2) + a(n-4) + 2*a(n-5) + 2*a(n-6) + a(n-7) - a(n-9) - a(n-10) - a(n-11) for n>15.

(End)

Crossrefs

Column k=5 of A242887.

Sequence in context: A366419 A309620 A291794 * A166621 A330082 A160275

Adjacent sequences: A321772 A321773 A321774 * A321776 A321777 A321778

Keyword

nonn

Author

Alois P. Heinz, Nov 18 2018

Status

approved