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A067296
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Fifth column of triangle A028364.
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2
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42, 90, 255, 785, 2529, 8398, 28511, 98462, 344720, 1220532, 4362438, 15718149, 57028063, 208164950, 763915215, 2816707650, 10429892340, 38768134380, 144600329250, 541036998090, 2030157909234, 7637910332556
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OFFSET
| 0,1
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FORMULA
| a(n)= A028364(n+4, 4) = sum(C(k)C(n+4-k), k=0..4), with the Catalan numbers C(n)=A000108(n).
a(n)= ((193n^4+1727*n^3+5303*n^2+6457*n+2520)/(8*(2*n+1)*(2*n+3)*(2*n+5)*(2*n+7)))*C(n+4).
G.f.: (c4(x)*c(x)-(c4(x)-1)/x)/x^4, with c4(x) := sum(C(k)*x^k, k=0..4) and c(x) g.f. for Catalan numbers A000108.
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CROSSREFS
| Cf. A067295 (fourth column).
Sequence in context: A172437 A160283 A019283 * A044180 A044561 A169680
Adjacent sequences: A067293 A067294 A067295 * A067297 A067298 A067299
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KEYWORD
| nonn,easy
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Feb 5 2002
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