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A122874 List of pairs n+7, 13-n, n >= 0. 1
7, 13, 8, 12, 9, 11, 10, 10, 11, 9, 12, 8, 13, 7, 14, 6, 15, 5, 16, 4, 17, 3, 18, 2, 19, 1, 20, 0, 21, -1, 22, -2, 23, -3, 24, -4, 25, -5, 26, -6, 27, -7, 28, -8, 29, -9, 30, -10, 31, -11, 32, -12, 33, -13, 34, -14, 35, -15, 36, -16, 37, -17, 38, -18, 39, -19, 40, -20, 41, -21, 42 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
FORMULA
a(n) = -a(n-1)+a(n-2)+a(n-3). G.f.: -(7+20*x+14*x^2)/((x-1)*(1+x)^2). [R. J. Mathar, Aug 07 2009]
MATHEMATICA
CoefficientList[Series[-(7 + 20 x + 14 x^2)/((x - 1) (1 + x)^2), {x, 0, 100}], x] (* Vincenzo Librandi, May 25 2014 *)
PROG
(Magma) &cat[[n+7, 13-n]: n in [0..30]]; // Vincenzo Librandi, May 25 2014
CROSSREFS
Sequence in context: A369717 A365346 A215990 * A066003 A115858 A114389
KEYWORD
sign,tabf,easy
AUTHOR
Stuart M. Ellerstein (ellerstein(AT)aol.com), Oct 23 2006
EXTENSIONS
Edited with better definition by Omar E. Pol and N. J. A. Sloane, Jan 02 2009
More terms from R. J. Mathar, Aug 07 2009
STATUS
approved

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Last modified March 29 06:57 EDT 2024. Contains 371265 sequences. (Running on oeis4.)