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 A054442 Second convolution of A001405 (central binomial numbers). 1
 1, 3, 9, 22, 54, 123, 281, 618, 1362, 2934, 6330, 13452, 28620, 60243, 126921, 265282, 554874, 1153506, 2399390, 4966740, 10286196, 21219038, 43790154, 90076452, 185353204, 380364108, 780786516, 1599015192, 3275589144 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA a(2*k)= -3*2^(2*k+1)+binomial(2*(k+1), k+1)*(4*k+7)/2, a(2*k+1)= -3*4^(k+1)+binomial(2*(k+2), k+2)*(2*k+5)/2, k >= 0. a(n)= A054336(n+2, 2) (third column of convolution triangle). G.f.: (1/(1-x-x^2*c(x^2)))^3, with c(x) the g.f. for the Catalan numbers A000108. CROSSREFS Cf. A000108, A001405, A054336, A045621. Sequence in context: A222083 A305612 A202882 * A192663 A114697 A032284 Adjacent sequences:  A054439 A054440 A054441 * A054443 A054444 A054445 KEYWORD easy,nonn AUTHOR Wolfdieter Lang, Mar 27 2000 STATUS approved

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Last modified June 2 14:21 EDT 2020. Contains 334787 sequences. (Running on oeis4.)