A224509 Expansion of (1-x)*(1-2*x)*(1-3*x)/(1-9*x+28*x^2-35*x^3+15*x^4-x^5).

1, 3, 10, 35, 125, 451, 1637, 5965, 21794, 79781, 292468, 1073296, 3941950, 14486721, 53264010, 195909180, 720769621, 2652351034, 9761957789, 35933354194, 132282020709, 487008295675, 1793068462212, 6602016250702, 24309222706566, 89511103102442

Offset: 0

Author

Philippe Deléham, Apr 08 2013

Keywords

• nonn
• easy

Comments

A diagonal of the square array A223968.

Links

• Index entries for linear recurrences with constant coefficients, signature (9,-28,35,-15,1)

Crossrefs

Cf. A223968

Formula

a(n) = A223968(n+1,n).

G.f.: (1-x)*(1-2*x)*(1-3*x)/(1-9*x+28*x^2-35*x^3+15*x^4-x^5).

a(n) = 9*a(n-1) - 28*a(n-2) + 35*a(n-3) - 15*a(n-4) + a(n-5) with a(0) = 1, a(1) = 3, a(2) = 10, a(3) = 35, a(4) = 125.