A076571 Binomial triangle based on factorials.
1, 1, 2, 2, 3, 5, 6, 8, 11, 16, 24, 30, 38, 49, 65, 120, 144, 174, 212, 261, 326, 720, 840, 984, 1158, 1370, 1631, 1957, 5040, 5760, 6600, 7584, 8742, 10112, 11743, 13700, 40320, 45360, 51120, 57720, 65304, 74046, 84158, 95901, 109601
Offset: 0
Examples
Rows start: 1; 1, 2; 2, 3, 5; 6, 8, 11, 16; 24, 30, 38, 49, 65; 120, 144, 174, 212, 261, 326;
Links
- G. C. Greubel, Rows n = 0..50 of the triangle, flattened
- E. Biondi, L. Divieti, and G. Guardabassi, Counting paths, circuits, chains and cycles in graphs: A unified approach, Canad. J. Math. 22 1970 22-35. See Table I.
- D. Dumont, Matrices d'Euler-Seidel, Sem. Loth. Comb. B05c (1981) 59-78.
Crossrefs
Programs
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Magma
A076571:= func< n,k| (&+[Binomial(k,j)*Factorial(n-j): j in [0..k]]) >; [A076571(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Oct 05 2023
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Mathematica
A076571[n_, k_]:= n!*Hypergeometric1F1[-k,-n,1]; Table[A076571[n,k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Oct 05 2023 *)
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SageMath
def A076571(n,k): return sum(binomial(k,j)*factorial(n-j) for j in range(k+1)) flatten([[A076571(n,k) for k in range(n+1)] for n in range(13)]) # G. C. Greubel, Oct 05 2023
Formula
T(n, k) = Sum_{j=0..k} binomial(k, j)*(n-j)!.
T(n, k) = T(n, k-1) + T(n-1, k-1) with T(n, 0) = n!.
T(n, n) = A000522(n).
Sum_{k=0..n} T(n, k) = A002627(n+1).
From G. C. Greubel, Oct 05 2023: (Start)
T(n, k) = n! * Hypergeometric1F1([-k], [-n], 1).
T(2*n, n) = A099022(n). (End)