login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A155659
a(n) = 8^n - 7^n + 1.
16
1, 2, 16, 170, 1696, 15962, 144496, 1273610, 11012416, 93864122, 791266576, 6612607850, 54878189536, 452866803482, 3719823438256, 30436810578890, 248242046141056, 2019169299698042, 16385984911571536, 132716292890482730, 1073129238309234976, 8664826172771491802
OFFSET
0,2
FORMULA
G.f.: 1/(1-8*x)-1/(1-7*x)+1/(1-x).
E.g.f.: exp(8*x)-exp(7*x)+exp(x).
a(n) = 15*a(n-1)-56*a(n-2)+42 with a(0) = 1, a(1) = 2. - Vincenzo Librandi, Jul 21 2010
MATHEMATICA
Table[8^n - 7^n + 1, {n, 0, 25}] (* Paolo Xausa, Aug 03 2024 *)
PROG
(PARI) a(n)=8^n-7^n+1 \\ Charles R Greathouse IV, Jun 11 2015
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 31 2009
STATUS
approved