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A277175
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Convolution of Catalan numbers and factorial numbers.
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4
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1, 2, 5, 15, 53, 222, 1120, 6849, 50111, 427510, 4142900, 44693782, 529276962, 6813205468, 94642629984, 1410507388421, 22445134308123, 379776665469030, 6808016435182620, 128886547350655050, 2569493300908367550, 53805226930896987540, 1180673761078007109840
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = Sum_{i=0..n} C(i) * (n-i)!.
a(n) ~ n! * (1 + 1/n + 2/n^2 + 7/n^3 + 31/n^4 + 163/n^5 + 979/n^6 + 6556/n^7 + 48150/n^8 + 383219/n^9 + 3275121/n^10 + ...), for coefficients see A277396. - Vaclav Kotesovec, Oct 13 2016
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MAPLE
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a:= proc(n) option remember; `if`(n<4, [1, 2, 5, 15][n+1],
((2*(n^4-n^3-19*n^2+48*n-5))*a(n-1)
-(n+1)*(n^4+9*n^3-90*n^2+226*n-160)*a(n-2)
+(2*(4*n^5-18*n^4-23*n^3+266*n^2-523*n+330))*a(n-3)
-(4*(n-2))*(n^2-4*n+5)*(2*n-5)^2*a(n-4))/
((n+1)*(n^2-6*n+10)))
end:
seq(a(n), n=0..30);
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MATHEMATICA
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Table[Sum[CatalanNumber[k]*(n - k)!, {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Oct 13 2016 *)
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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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