A156788 Triangle T(n, k) = binomial(n, k)*A000166(n-k)*k^n with T(0, 0) = 1, read by rows.
1, 0, 1, 0, 0, 4, 0, 3, 0, 27, 0, 8, 96, 0, 256, 0, 45, 640, 2430, 0, 3125, 0, 264, 8640, 29160, 61440, 0, 46656, 0, 1855, 118272, 688905, 1146880, 1640625, 0, 823543, 0, 14832, 1899520, 16166304, 41287680, 43750000, 47029248, 0, 16777216, 0, 133497, 34172928, 438143580, 1453326336, 2214843750, 1693052928, 1452729852, 0, 387420489
Offset: 0
Examples
Triangle begins as: 1; 0, 1; 0, 0, 4; 0, 3, 0, 27; 0, 8, 96, 0, 256; 0, 45, 640, 2430, 0, 3125; 0, 264, 8640, 29160, 61440, 0, 46656; 0, 1855, 118272, 688905, 1146880, 1640625, 0, 823543; 0, 14832, 1899520, 16166304, 41287680, 43750000, 47029248, 0, 16777216;
References
- J. Riordan, Combinatorial Identities, Wiley, 1968, p.194.
Links
- G. C. Greubel, Rows n = 0..50 of the triangle, flattened
Programs
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Mathematica
A000166[n_]:= A000166[n]= If[n==0, 1, n*A000166[n-1] + (-1)^n]; T[n_, k_]:= If[n==0, 1, Binomial[n, k]*A000166[n-k]*k^n]; Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jun 10 2021 *)
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Sage
def A000166(n): return 1 if (n==0) else n*A000166(n-1) + (-1)^n def A156788(n,k): return 1 if (n==0) else binomial(n,k)*k^n*A000166(n-k) flatten([[A156788(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jun 10 2021
Formula
T(n, k) = binomial(n, k)*A000166(n-k)*k^n with T(0, 0) = 1.
T(n, k) = binomial(n, k)*b(n-k)*k^n, where b(n) = n*b(n-1) + (-1)^n and b(0) = 1.
Sum_{k=0..n} T(n, k) = A137341(n).
From G. C. Greubel, Jun 10 2021: (Start)
T(n, 1) = A000240(n).
T(n, n) = A000312(n). (End)
Extensions
Edited by G. C. Greubel, Jun 10 2021