A155598 - OEIS

A155598

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

1, 6, 46, 336, 2386, 16776, 117586, 823416, 5764546, 40353096, 282474226, 1977324696, 13841283106, 96889002216, 678223056466, 4747561477176, 33232930504066, 232630513856136, 1628413597648306, 11398895184848856

(list; graph; refs; listen; history; text; internal format)

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)=6 - Vincenzo Librandi, Jul 21 2010

a(0)=1, a(1)=6, a(2)=46, a(n) = 10*a(n-1)-23*a(n-2)+14*a(n-3). - Harvey P. Dale, Feb 28 2013

a(n) = A190540(n)+1. - R. J. Mathar, Mar 10 2022

MATHEMATICA

Table[7^n-2^n+1, {n, 0, 20}] (* or *) LinearRecurrence[{10, -23, 14}, {1, 6, 46}, 20] (* Harvey P. Dale, Feb 28 2013 *)

PROG

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

CROSSREFS

Cf. A074501, A020515, A155588, A155590, A155592, A155593, A155594, A155596, A155597.

Sequence in context: A325947 A240779 A073507 * A190005 A334609 A253654

Adjacent sequences: A155595 A155596 A155597 * A155599 A155600 A155601

KEYWORD

nonn,easy

AUTHOR

Mohammad K. Azarian, Jan 25 2009

STATUS

approved