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A182428
a(n) = 2n(19-n).
1
0, 36, 68, 96, 120, 140, 156, 168, 176, 180, 180, 176, 168, 156, 140, 120, 96, 68, 36, 0, -40, -84, -132, -184, -240, -300, -364, -432, -504, -580, -660, -744, -832, -924, -1020, -1120, -1224, -1332, -1444, -1560, -1680, -1804, -1932, -2064, -2200, -2340, -2484, -2632, -2784, -2940, -3100, -3264, -3432, -3604, -3780, -3960, -4144, -4332, -4524, -4720, -4920, -5124
OFFSET
0,2
LINKS
B. Khesin and S. Tabachnikov, editors, Memories of Vladimir Arnold, Notices Amer. Math. Soc., 59 (No. 4, 2012), pp. 482-502 (see illustration of Arnold lecturing on page 495).
FORMULA
G.f.: 4*x*(9-10*x)/(1-x)^3. - Bruno Berselli, May 23 2012
MATHEMATICA
Table[2 n (19 - n), {n, 0, 61}] (* Bruno Berselli, May 23 2012 *)
PROG
(PARI) a(n)=2*n*(19-n) \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
Sequence in context: A211724 A250771 A068144 * A208128 A260919 A247381
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Apr 28 2012
STATUS
approved