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A054442
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Second convolution of A001405 (central binomial numbers).
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1
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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; internal format)
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OFFSET
| 0,2
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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.
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CROSSREFS
| Cf. A000108, A001405, A054336, A045621.
Sequence in context: A001628 A099166 A202882 * A192663 A114697 A032284
Adjacent sequences: A054439 A054440 A054441 * A054443 A054444 A054445
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KEYWORD
| easy,nonn
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Mar 27 2000
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