A226941 Expansion of 1/((1-x)(1-3x)(1-6x)(1-10x)(1-15x)).

1, 35, 798, 15178, 262739, 4310073, 68451856, 1065454016, 16372593237, 249520885471, 3782278181474, 57129692163414, 860905800344695, 12953222527379429, 194694881199600852, 2924389779305546572, 43905519073297744313, 658979550560400579147, 9888661146758667705190

Offset

1,2

Comments

Note that the denominator has 5 triangular numbers: 1, 3, 6, 10, and 15.

Links

Table of n, a(n) for n=1..19.

Index entries for linear recurrences with constant coefficients, signature (35,-427,2193,-4500,2700).

Formula

a(n) = (15^(n+4) - 6*10^(n+4) + 14*6^(n+4) - 15*3^(n+4) + 6)/7560.

a(n) = 35*a(n-1) - 427*a(n-2) + 2193*a(n-3) - 4500*a(n-4) + 2700*a(n-5) for n > 5. - Chai Wah Wu, Aug 10 2020

Crossrefs

Column k = 4 of A080248. Cf. A003462, A016211, A021514.

Sequence in context: A066553 A137309 A028024 * A249883 A249884 A223957

Adjacent sequences: A226938 A226939 A226940 * A226942 A226943 A226944

Keyword

nonn

Author

Yahia Kahloune, Jun 23 2013

Status

approved