A016230 Expansion of 1/((1-x)(1-5x)(1-7x)).

1, 13, 122, 1010, 7851, 58863, 431572, 3118660, 22318901, 158673713, 1122923022, 7921496310, 55755649951, 391815428563, 2750337394472, 19290508733960, 135224296001001, 947523746323413, 6637434595845922

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Index entries for linear recurrences with constant coefficients, signature (13,-47,35).

Formula

a(0)=1, a(1)=13, a(n)=12*a(n-1)-35*a(n-2)+1. - Vincenzo Librandi, Feb 10 2011

a(n) = (2*7^(n+2) - 3*5^(n+2) + 1)/24. - Yahia Kahloune, Aug 13 2013

Maple

a:=n->sum((7^(n-j)-5^(n-j))/2, j=0..n): seq(a(n), n=1..19); # Zerinvary Lajos, Jan 15 2007

Prog

(PARI) a(n) = (2*7^(n+2) - 3*5^(n+2) + 1)/24; \\ Joerg Arndt, Aug 13 2013

Crossrefs

Sequence in context: A297594 A326569 A339057 * A327961 A278276 A201382

Adjacent sequences: A016227 A016228 A016229 * A016231 A016232 A016233

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved