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A147601 First differences of A132355. 0
7, 4, 21, 8, 35, 12, 49, 16, 63, 20, 77, 24, 91, 28, 105, 32, 119, 36, 133, 40, 147, 44, 161, 48, 175, 52, 189, 56, 203, 60, 217, 64, 231, 68, 245, 72, 259, 76, 273, 80, 287, 84, 301, 88, 315, 92, 329, 96, 343, 100, 357 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..50.

Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

FORMULA

G.f. ( 7+4*x+7*x^2 ) / ( (x-1)^2*(1+x)^2 ). - R. J. Mathar, Jun 21 2011

a(2n) = A147587(n). a(2n+1) = 4*(n+1).

a(n) = (9+5*(-1)^n)*(1+n)/2. - Colin Barker, Jun 06 2012

MATHEMATICA

Differences[Sort[Table[9n^2+2n, {n, -30, 30}]]] (* or *) LinearRecurrence[ {0, 2, 0, -1}, {7, 4, 21, 8}, 60] (* Harvey P. Dale, Jun 04 2017 *)

CROSSREFS

Sequence in context: A279942 A279998 A063632 * A075536 A280336 A085047

Adjacent sequences:  A147598 A147599 A147600 * A147602 A147603 A147604

KEYWORD

nonn,easy

AUTHOR

Paul Curtz, Nov 08 2008

STATUS

approved

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Last modified January 26 18:17 EST 2022. Contains 350599 sequences. (Running on oeis4.)