A081680 A sum of decreasing powers.

1, 2, 4, 23, 274, 2927, 27094, 228923, 1827634, 14069687, 105715534, 781107923, 5702856394, 41273440847, 296753044774, 2122921300523, 15127554995554, 107462125890407, 761485887090814, 5385095865086723, 38019827430709114

Offset

0,2

Comments

Binomial transform of A081679

Links

Table of n, a(n) for n=0..20.

Index entries for linear recurrences with constant coefficients, signature (25,-245,1175,-2754,2520).

Formula

a(n)=(7^n-6^n-5^n-4^n+4*3^n)/2.

G.f.: -(1083*x^4-762*x^3+199*x^2-23*x+1)/((3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)*(7*x-1)). [Colin Barker, Sep 07 2012]

Mathematica

LinearRecurrence[{25, -245, 1175, -2754, 2520}, {1, 2, 4, 23, 274}, 30] (* Harvey P. Dale, Feb 19 2018 *)

Crossrefs

Cf. A081681.

Sequence in context: A009313 A009317 A209024 * A269573 A147761 A214299

Adjacent sequences: A081677 A081678 A081679 * A081681 A081682 A081683

Keyword

easy,nonn

Author

Paul Barry, Mar 30 2003

Status

approved