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A048491
a(n) = T(8,n), array T given by A048483.
6
1, 10, 28, 64, 136, 280, 568, 1144, 2296, 4600, 9208, 18424, 36856, 73720, 147448, 294904, 589816, 1179640, 2359288, 4718584, 9437176, 18874360, 37748728, 75497464, 150994936, 301989880, 603979768, 1207959544, 2415919096
OFFSET
0,2
COMMENTS
n-th difference of a(n), a(n-1), ..., a(0) is (9, 9, 9, ...).
FORMULA
a(n) = 9 * 2^n - 8. - Ralf Stephan
Equals binomial transform of [1, 9, 9, 9, ...]. - Gary W. Adamson, Apr 29 2008
a(n) = 2*a(n-1) + 8, with a(0)=1. - Vincenzo Librandi, Aug 06 2010
a(n) = 2*A053209(n), n>0. - Philippe Deléham, Apr 15 2013
a(n) = 3*a(n-1) - 2*a(n-2) with a(0)=1, a(1)=10. - Philippe Deléham, Apr 15 2013
G.f.: (1+7*x)/((1-x)*(1-2*x)). - Philippe Deléham, Apr 15 2013
MATHEMATICA
a=1; lst={a}; k=9; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 16 2008 *)
9*2^Range[0, 30]-8 (* Harvey P. Dale, May 14 2021 *)
CROSSREFS
Sequence in context: A053790 A364694 A269441 * A124703 A333241 A251319
KEYWORD
nonn,easy
STATUS
approved