A155590 a(n) = 7^n+2^n-1^n.

1, 8, 52, 350, 2416, 16838, 117712, 823670, 5765056, 40354118, 282476272, 1977328790, 13841291296, 96889018598, 678223089232, 4747561542710, 33232930635136, 232630514118278, 1628413598172592, 11398895185897430

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (10,-23,14).

Formula

G.f.: 1/(1-7*x)+1/(1-2*x)-1/(1-x). E.g.f.: e^(7*x)+e^(2*x)-e^x.

a(n) = 9*a(n-1)-14*a(n-2)-6 with a(0)=1, a(1)=8 - Vincenzo Librandi, Jul 21 2010

a(n) = A074602(n)-1. - R. J. Mathar, Mar 10 2022

Prog

(PARI) a(n)=7^n+2^n-1 \\ Charles R Greathouse IV, Sep 24 2015

Crossrefs

Cf. A074501, A074600, A005057, A005056, A099393, A155588, A155590.

Sequence in context: A205218 A287813 A126503 * A130153 A359126 A199700

Adjacent sequences: A155587 A155588 A155589 * A155591 A155592 A155593

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 24 2009

Status

approved