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A152818
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Array read by antidiagonals: A(n,k) = (k+1)^n*(n+k)!/n!.
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14
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1, 1, 1, 1, 4, 2, 1, 12, 18, 6, 1, 32, 108, 96, 24, 1, 80, 540, 960, 600, 120, 1, 192, 2430, 7680, 9000, 4320, 720, 1, 448, 10206, 53760, 105000, 90720, 35280, 5040, 1, 1024, 40824, 344064, 1050000, 1451520, 987840, 322560, 40320
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OFFSET
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0,5
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COMMENTS
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A009998/A119502 gives triangle of unreduced coefficients of polynomials defined by A152650/A152656. a(n) gives numerators with denominators n! for each row.
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LINKS
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FORMULA
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E.g.f. for array as a triangle: exp(x)/(1-t*x*exp(x)) = 1+(1+t)*x+(1+4*t+2*t^2)*x^2/2! + (1+12*t+18*t^2+6*t^3)*x^3/3! + .... E.g.f. is int {z = 0..inf} exp(-z)*F(x,t*z), (x and t chosen sufficiently small for the integral to converge), where F(x,t) = exp(x*(1+t*exp(x))) is the e.g.f. for A154372. - Peter Bala, Oct 09 2011
From the e.g.f., the row polynomials R(n,t) satisfy the recursion R(n,t) = 1 + t*sum {k = 0..n-1} n!/(k!*(n-k-1)!)*R(n-k-1,t). The polynomials 1/n!*R(n,x) are the polynomials P(n,x) of A152650.
Sum_{k=0..n} T(n, k) = A072597(n) (antidiagonal sums). (End)
T(n, k) = (k+1)^(n-k) * k! * binomial(n, k) (antidiagonal triangle).
Sum_{k=0..n} (-1)^k*T(n, k) = A089148(n). (End)
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EXAMPLE
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Array begins:
1, 1, 2, 6, 24, 120, ...
1, 4, 18, 96, 600, 4320, ...
1, 12, 108, 960, 9000, 90720, ...
1, 32, 540, 7680, 105000, 1451520, ...
1, 80, 2430, 53760, 1050000, 19595520, ...
1, 192, 10206, 344064, 9450000, 235146240, ...
1, 448, 40824, 2064384, 78750000, 2586608640, ...
1, 1024, 157464, 11796480, 618750000, 26605117440, ...
1, 2304, 590490, 64880640, 4640625000, 259399895040, ... (End)
Antidiagonal triangle:
1;
1, 1;
1, 4, 2;
1, 12, 18, 6;
1, 32, 108, 96, 24;
1, 80, 540, 960, 600, 120;
1, 192, 2430, 7680, 9000, 4320, 720;
1, 448, 10206, 53760, 105000, 90720, 35280, 5040;
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MATHEMATICA
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len= 45; m= 1 + Ceiling[Sqrt[len]]; Sort[Flatten[#, 1] &[MapIndexed[ {(2 +#2[[1]]^2 +(#2[[2]] -1)*#2[[2]] +#2[[1]]*(2*#2[[2]] -3))/ 2, #1}&, Table[(k+1)^n*(n+k)!/n!, {n, 0, m}, {k, 0, m}], {2}]]][[All, 2]][[1 ;; len]] (* From Jean-François Alcover, May 27 2011 *)
T[n_, k_]:= (k+1)^(n-k)*k!*Binomial[n, k];
Table[T[n, k], {n, 0, 15}, {k, 0, n}]//Flatten (* G. C. Greubel, Apr 10 2023 *)
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PROG
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(Sage)
R.<x> = ZZ[]
P = add((n-k+1)^k*x^(n-k+1)*factorial(n)/factorial(k) for k in (0..n))
return P.coefficients()
(Magma)
A152818:= func< n, k | (k+1)^(n-k)*Factorial(k)*Binomial(n, k) >;
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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