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A014926 a(1)=1, a(n) = n*11^(n-1) + a(n-1). 1
1, 23, 386, 5710, 78915, 1045221, 13446148, 169343516, 2098573445, 25678050355, 310989720966, 3734729768298, 44534298665671, 527852268680705, 6224099772429320, 73060070483079736 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..900

Index entries for linear recurrences with constant coefficients, signature (23,-143,121).

FORMULA

a(n) = (1/100)*(1+11^n*(10*n-1)), with n >= 1. - Paolo P. Lava, Jan 13 2009

a(1)=1, a(2)=23, a(n) = 22*a(n-1) - 121*a(n-2) + 1. - Vincenzo Librandi, Oct 23 2012

G.f.: x/((1 - x)*(1 - 11*x)^2). - Vincenzo Librandi, Oct 23 2012

MATHEMATICA

CoefficientList[Series[1/((1 - x)(1 - 11*x)^2), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 23 2012 *)

PROG

(MAGMA) I:=[1, 23]; [n le 2 select I[n] else 22*Self(n-1) - 121*Self(n-2) + 1: n in [1..30]]; // Vincenzo Librandi, Oct 23 2012

(PARI) a(n) = (1+11^n*(10*n-1))/100; \\ Jinyuan Wang, Mar 11 2020

CROSSREFS

Sequence in context: A264321 A285234 A046493 * A016267 A142821 A245805

Adjacent sequences:  A014923 A014924 A014925 * A014927 A014928 A014929

KEYWORD

nonn,easy

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified September 18 07:39 EDT 2020. Contains 337166 sequences. (Running on oeis4.)