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A158269
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a(n) = coefficient of x^n in the (2^n)-th iteration of x*C(x) where C(x) is the Catalan function (A000108), for n>=1.
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1
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1, 4, 72, 4760, 1196800, 1185344160, 4704904407424, 75251548566631296, 4850542035077717613312, 1257976093502471658023554560, 1310350352604009611135942297681920
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OFFSET
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1,2
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LINKS
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PROG
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(PARI) {a(n)=local(G=serreverse(x-x^2+O(x^(n+2)))); for(i=2, n+1, G=subst(G, x, G)); polcoeff(G, n)}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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