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A048477 a(n) = T(5,n), array T given by A048472. 1
1, 7, 25, 73, 193, 481, 1153, 2689, 6145, 13825, 30721, 67585, 147457, 319489, 688129, 1474561, 3145729, 6684673, 14155777, 29884417, 62914561, 132120577, 276824065, 578813953, 1207959553, 2516582401, 5234491393, 10871635969, 22548578305, 46707769345 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

n-th difference of a(n), a(n-1), ..., a(0) is (6, 12, 18, ...).

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (5,-8,4).

FORMULA

a(n) = 6*n * 2^(n-1) + 1.

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

a(n) = 5*a(n-1)-8*a(n-2)+4*a(n-3) for n>2. - Colin Barker, Feb 18 2016

PROG

(MAGMA) [6*n * 2^(n-1) + 1: n in [0..30]]; // Vincenzo Librandi, Sep 23 2011

(PARI) {a(n) = if( n<0, 0, 3 * n * 2^n + 1)}; /* Michael Somos, May 13 2014 */

(PARI) Vec((1+2*x-2*x^2)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Colin Barker, Feb 18 2016

CROSSREFS

Sequence in context: A155221 A213569 A299269 * A294837 A117152 A155281

Adjacent sequences:  A048474 A048475 A048476 * A048478 A048479 A048480

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified July 18 15:26 EDT 2019. Contains 325143 sequences. (Running on oeis4.)