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 A113647 Triangle of numbers related to the generalized Catalan sequence C(2;n+1)=A064062(n+1), n>=0. 8
 1, 1, 3, 1, 7, 13, 1, 15, 41, 67, 1, 31, 113, 247, 381, 1, 63, 289, 783, 1545, 2307, 1, 127, 705, 2271, 5361, 9975, 14589, 1, 255, 1665, 6207, 16929, 36879, 66057, 95235, 1, 511, 3841, 16255, 50113, 123871, 255985, 446455, 636925, 1, 1023, 8705, 41215, 141441 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS This triangle, called Y(2,1), appears in the totally asymmetric exclusion process for the (unphysical) values alpha=2, beta=1. See the Derrida et al. refs. given under A064094, where the triangle entries are called Y_{N,K} for given alpha and beta. The main diagonal (M=1) gives the generalized Catalan sequence C(2,n):=A064062(n). The diagonal sequences give A064062(n+1), A115137, A115150-A115153, for n+1>= M=1,..,6. LINKS W. Lang: First 10 rows. FORMULA a(n, n+1)=A064062(n+1) (main diagonal with M=1); a(n, n-M+2)= a(n, n-M+1) + 2*a(n-1, n-M+2), M>=2; a(n, 1)=1; n>=0. G.f. for diagonal sequence M=1: GY(1, x):=(2*c(2*x)-1)/(1+x) with c(x) g.f. of A000108 (Catalan); for M=2: GY(2, x)=(1-2*x)*GY(1, x)-1; for M>=3: GY(M, x)= GY(M-1, x) -2*x*GY(M-2, x) + x^(M-2). G.f. for diagonal sequence M (solution to the above given recurrence): GY(M, x)= (x^(M-1)/(1+x))*( 2^(M+1)*x*(p(M, 2*x)-(2*x)*p(M+1, 2*x)*c(2*x))+1), with c(x) g.f. of A000108 (Catalan) and p(n, x):= -((1/sqrt(x))^(n+1))*S(n-1, 1/sqrt(x)) with Chebyshev's S(n, x) polynomials given in A049310. EXAMPLE [1];[1,3];[1,7,13];[1,15,41,67];[1,31,113,247,381];... 113=a(4,3)= a(4,2) + 2*a(3,3)= 31 + 2*41. CROSSREFS Row sums give A115136. Sequence in context: A171501 A196845 A218592 * A161380 A051927 A194595 Adjacent sequences:  A113644 A113645 A113646 * A113648 A113649 A113650 KEYWORD nonn,easy,tabl AUTHOR Wolfdieter Lang, Jan 13 2006 STATUS approved

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Last modified May 19 00:49 EDT 2013. Contains 225428 sequences.