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 A147601 First differences of A132355. 1
 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 G. C. Greubel, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1). FORMULA G.f.: ( 7+4*x+7*x^2 ) / ((1-x)*(1+x))^2. - R. J. Mathar, Jun 21 2011 a(2*n) = A147587(n). a(2*n+1) = 4*(n+1). a(n) = (9 + 5*(-1)^n)*(1+n)/2. - Colin Barker, Jun 06 2012 E.g.f.: (1/2)*(5*(1-x)*exp(-x) + 9*(1+x)*exp(x)). - G. C. Greubel, Oct 25 2022 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 *) PROG (Magma) [(9 + 5*(-1)^n)*(1+n)/2: n in [0..60]]; // G. C. Greubel, Oct 25 2022 (SageMath) [(9 + 5*(-1)^n)*(1+n)/2 for n in range(61)] # G. C. Greubel, Oct 25 2022 CROSSREFS Cf. A132355, A147587. 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 February 5 15:20 EST 2023. Contains 360086 sequences. (Running on oeis4.)