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 A064310 Generalized Catalan numbers C(-1; n). 11
 1, 1, 0, 1, -2, 6, -18, 57, -186, 622, -2120, 7338, -25724, 91144, -325878, 1174281, -4260282, 15548694, -57048048, 210295326, -778483932, 2892818244, -10786724388, 40347919626, -151355847012, 569274150156 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS See triangle A064334 with columns m built from C(-m; n), m >= 0, also for Derrida et al. references. Unsigned sequence with a(0) := 0 is A000957 (Fine). LINKS G. C. Greubel, Table of n, a(n) for n = 0..1000 Paul Barry and Aoife Hennessy, Generalized Narayana Polynomials, Riordan Arrays, and Lattice Paths, Journal of Integer Sequences, Vol. 15, 2012, #12.4.8. [N. J. A. Sloane, Oct 08 2012] P. Pagacz, M. Wojtylak, On the spectral properties of a class of H-selfadjoint random matrices and the underlying combinatorics, arXiv:1310.2122 [math.PR], 2013. FORMULA a(n) = Sum_{m=0..n-1} (-1)^m*(n-m)*binomial(n-1+m, m)/n. a(n) = ((1/2)^n)*(1 + Sum_{k=0..n-1} C(k)*(-2)^k ), n >= 1, a(0)= 1, with C(n)=A000108(n) (Catalan). G.f.: (1+x*c(-x)/2)/(1-x/2) = 1/(1-x*c(-x)) with c(x) g.f. of Catalan numbers A000108. a(n) = Sum_{k=0..n} (-1)^(n-k)*A106566(n, k). - Philippe Deléham, Sep 18 2005 (-1)^n*a(n) = Sum_{k=0..n} A039599(n,k)*(-2)^k. - Philippe Deléham, Mar 13 2007 Conjecture: 2*n*a(n) + (7*n-12)*a(n-1) + 2*(-2*n+3)*a(n-2) = 0. - R. J. Mathar, Dec 02 2012 MATHEMATICA a[n_]:= (1/2)^n*(1 + Sum[ CatalanNumber[k]*(-2)^k, {k, 0, n-1}]); Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Jul 17 2013 *) PROG (PARI) {a(n) = (1 + sum(k=0, n-1, (-2)^k*binomial(2*k, k)/(k+1)))/2^n}; vector(30, n, n--; a(n)) \\ G. C. Greubel, Feb 27 2019 (MAGMA) [1] cat [(1 +(&+[(-2)^k*Binomial(2*k, k)/(k+1): k in [0..n-1]]))/2^n: n in [1..30]]; // G. C. Greubel, Feb 27 2019 (Sage) [1] + [(1 +sum((-2)^k*catalan_number(k) for k in (0..n-1)))/2^n for n in (1..30)] # G. C. Greubel, Feb 27 2019 CROSSREFS Cf. A000108, A000957, A039599, A106566. Sequence in context: A071721 A125306 A209797 * A126983 A104629 A000957 Adjacent sequences:  A064307 A064308 A064309 * A064311 A064312 A064313 KEYWORD sign,easy AUTHOR Wolfdieter Lang, Sep 21 2001 STATUS approved

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Last modified October 21 06:01 EDT 2019. Contains 328291 sequences. (Running on oeis4.)