A048490 a(n) = T(7,n), array T given by A048483.

1, 9, 25, 57, 121, 249, 505, 1017, 2041, 4089, 8185, 16377, 32761, 65529, 131065, 262137, 524281, 1048569, 2097145, 4194297, 8388601, 16777209, 33554425, 67108857, 134217721, 268435449, 536870905, 1073741817, 2147483641, 4294967289, 8589934585

Offset

0,2

Comments

n-th difference of a(n), a(n-1), ..., a(0) is (8, 8, 8, ...).

Links

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3,-2).

Formula

a(n) = 8 * 2^n - 7. - Ralf Stephan, Jan 09 2009

Equals binomial transform of [1, 8, 8, 8, ...]. - Gary W. Adamson, Apr 29 2008

a(n) = 2*a(n-1) + 7 for n > 0, a(0)=1. - Vincenzo Librandi, Aug 06 2010

For n>=1, a(n) = 6<+>(n+3), where the operation <+> is defined in A206853. - Vladimir Shevelev, Feb 17 2012

From Colin Barker, Nov 26 2014: (Start)

a(n) = 3*a(n-1) - 2*a(n-2).

G.f.: (6*x+1) / ((x-1)*(2*x-1)). (End)

Mathematica

a=1; lst={a}; k=8; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 16 2008 *)

Prog

(PARI) Vec((6*x+1)/((x-1)*(2*x-1)) + O(x^100)) \\ Colin Barker, Nov 26 2014

Crossrefs

Sequence in context: A269440 A234038 A304033 * A113828 A099971 A124702

Adjacent sequences: A048487 A048488 A048489 * A048491 A048492 A048493

Keyword

nonn,easy

Author

Clark Kimberling

Extensions

More terms from Colin Barker, Nov 26 2014

Status

approved