A081687 A sum of decreasing powers.

1, 2, 2, 20, 542, 8132, 94502, 964700, 9138782, 82619732, 724180502, 6213565580, 52507598222, 438786732932, 3636161064902, 29939329241660, 245281233244862, 2001531240407732, 16280816416067702, 132088684297864940

Offset

0,2

Comments

Binomial transform of A081686

Links

Table of n, a(n) for n=0..19.

Index entries for linear recurrences with constant coefficients, signature (30,-355,2070,-5944,6720).

Formula

a(n)=8^n-7^n-6^n-5^n+3*4^n.

G.f. -(2456*x^4-1400*x^3+297*x^2-28*x+1)/((4*x-1)*(5*x-1)*(6*x-1)*(7*x-1)*(8*x-1)). [Colin Barker, Aug 12 2012]

Crossrefs

Cf. A081890.

Sequence in context: A350466 A184717 A134046 * A082811 A014353 A353101

Adjacent sequences: A081684 A081685 A081686 * A081688 A081689 A081690

Keyword

easy,nonn

Author

Paul Barry, Mar 30 2003

Extensions

Signature corrected by Colin Barker, Sep 07 2012

Status

approved