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A129428 Centered 47-gonal numbers. 1
1, 48, 142, 283, 471, 706, 988, 1317, 1693, 2116, 2586, 3103, 3667, 4278, 4936, 5641, 6393, 7192, 8038, 8931, 9871, 10858, 11892, 12973, 14101, 15276, 16498, 17767, 19083, 20446, 21856, 23313, 24817, 26368, 27966, 29611, 31303, 33042, 34828, 36661, 38541 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

FORMULA

a(n) = 1+(47/2)*n+(47/2)*n^2.

a(n) = 3*a(n-1)-3*a(n-2)+a(n-3). G.f.: -(x^2+45*x+1) / (x-1)^3. - Colin Barker, Jul 27 2013

MATHEMATICA

LinearRecurrence[{3, -3, 1}, {1, 48, 142}, 70] (* Vincenzo Librandi, Sep 09 2016 *)

PROG

(MAGMA) [1+(47/2)*n+(47/2)*n^2: n in [0..50]]; // Vincenzo Librandi, Sep 09 2016

(PARI) a(n)=47*n*(n+1)/2+1 \\ Charles R Greathouse IV, Jun 17 2017

CROSSREFS

Cf. A095311, A130566, A130859, A130876.

Sequence in context: A244380 A260493 A003502 * A039496 A044380 A044761

Adjacent sequences:  A129425 A129426 A129427 * A129429 A129430 A129431

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Oct 06 2007, based on a suggestion from an unknown correspondent in 2004.

STATUS

approved

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Last modified April 19 07:15 EDT 2021. Contains 343105 sequences. (Running on oeis4.)