OFFSET
0,8
LINKS
Paolo Xausa, Table of n, a(n) for n = 0..11475 (antidiagonals 0..150 of the square, flattened).
FORMULA
A(n, k) = Sum_{j=0..n} E(n, j)*k^j, where E(n, k) = A173018(n, k).
A(n, 1) = n!*[x^n] 1/(1-x).
A(n, k) = n!*[x^n] (k-1)/(k - exp((k-1)*x)) for k != 1.
A(n, k) = PolyLog(-n, 1/k)*(k-1)^(n+1)/k for k >= 2.
EXAMPLE
Array begins:
[0] 1, 1, 1, 1, 1, 1, 1, ... A000012
[1] 1, 1, 1, 1, 1, 1, 1, ... A000012
[2] 1, 2, 3, 4, 5, 6, 7, ... A000027
[3] 1, 6, 13, 22, 33, 46, 61, ... A028872
[4] 1, 24, 75, 160, 285, 456, 679, ...
[5] 1, 120, 541, 1456, 3081, 5656, 9445, ...
[6] 1, 720, 4683, 15904, 40005, 84336, 158095, ...
[7] 1, 5040, 47293, 202672, 606033, 1467376, 3088765, ...
[8] 1, 40320, 545835, 2951680, 10491885, 29175936, 68958295, ...
[9] 1, 362880, 7087261, 48361216, 204343641, 652606336, 1731875605, ...
Seen as a triangle:
[0] [1]
[1] [1, 1]
[2] [1, 1, 1]
[3] [1, 2, 1, 1]
[4] [1, 6, 3, 1, 1]
[5] [1, 24, 13, 4, 1, 1]
[6] [1, 120, 75, 22, 5, 1, 1]
[7] [1, 720, 541, 160, 33, 6, 1, 1]
[8] [1, 5040, 4683, 1456, 285, 46, 7, 1, 1]
[9] [1, 40320, 47293, 15904, 3081, 456, 61, 8, 1, 1]
MAPLE
# Prints array by row.
A := (n, k) -> add(combinat:-eulerian1(n, j)*k^j, j=0..n):
seq(print(seq(A(n, k), k=0..10)), n=0..8);
# Alternative:
egf := n -> `if`(n=1, 1/(1-x), (n-1)/(n - exp((n-1)*x))):
ser := n -> series(egf(n), x, 21):
for n from 0 to 6 do seq(n!*coeff(ser(k), x, n), k=0..9) od;
# Or:
A := (n, k) -> if k = 0 or n = 0 then 1 elif k = 1 then n! else
polylog(-n, 1/k)*(k-1)^(n+1)/k fi:
for n from 0 to 6 do seq(A(n, k), k=0..9) od;
MATHEMATICA
A332700[n_, k_] := n! + Sum[j! StirlingS2[n, j] (k-1)^(n-j), {j, n-1}];
Table[A332700[n-k, k], {n, 0, 10}, {k, 0, n}] (* Paolo Xausa, Feb 01 2024 *)
PROG
(Sage)
def T(n, k):
return sum(factorial(j)*stirling_number2(n, j)*(k-1)^(n-j) for j in range(n+1))
for n in range(8): print([T(n, k) for k in range(8)])
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Peter Luschny, Feb 28 2020
STATUS
approved