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 A015260 Gaussian binomial coefficient [ n,2 ] for q = -9. 3
 1, 73, 5986, 484210, 39226915, 3177326971, 257363962948, 20846476694116, 1688564650965445, 136773736379522605, 11078672649879436966, 897372484611991440598, 72687171253825493271271, 5887660871557577275727455, 476900530596184348447133320 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 REFERENCES J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969. I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99. M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351. LINKS Vincenzo Librandi, Table of n, a(n) for n = 2..200 Index entries for linear recurrences with constant coefficients, signature (73, 657, -729). FORMULA G.f.: x^2/((1-x)*(1+9*x)*(1-81*x)). a(2) = 1, a(3) = 73, a(4) = 5986, a(n) = 73*a(n-1) + 657*a(n-2) - 729*a(n-3). - Vincenzo Librandi, Oct 27 2012 MATHEMATICA Table[QBinomial[n, 2, -9], {n, 2, 20}] (* Vincenzo Librandi, Oct 27 2012 *) PROG (Sage) [gaussian_binomial(n, 2, -9) for n in range(2, 15)] # Zerinvary Lajos, May 27 2009 (MAGMA) I:=[1, 73, 5986]; [n le 3 select I[n] else 73*Self(n-1) + 657*Self(n-2) - 729*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Oct 27 2012 CROSSREFS Sequence in context: A093273 A183540 A022242 * A089788 A292013 A192765 Adjacent sequences:  A015257 A015258 A015259 * A015261 A015262 A015263 KEYWORD nonn,easy AUTHOR Olivier Gérard, Dec 11 1999 STATUS approved

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Last modified September 25 09:48 EDT 2020. Contains 337336 sequences. (Running on oeis4.)