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A338874
Array T(n, m) read by ascending antidiagonals: denominators of shifted Bernoulli numbers B(n, m) where m >= 0.
4
1, 1, 1, 1, 2, 1, 1, 6, 6, 1, 1, 1, 36, 24, 1, 1, 30, 180, 1440, 120, 1, 1, 1, 1080, 11520, 7200, 720, 1, 1, 42, 9072, 2419200, 672000, 1814400, 5040, 1, 1, 1, 90720, 2322432, 60480000, 435456000, 12700800, 40320, 1, 1, 30, 38880, 232243200, 207360000, 548674560000, 21337344000, 270950400, 362880, 1
OFFSET
0,5
LINKS
Takao Komatsu, Shifted Bernoulli numbers and shifted Fubini numbers, Linear and Nonlinear Analysis, Volume 6, Number 2, 2020, 245-263.
FORMULA
T(n, m) = denominator(B(n, m)).
B(n, m) = [x^n] n!*x^m/(exp(x) - E_m(x) + x^m), where E_m(x) = Sum_{n=0..m} x^n/n! (see Equation 2.1 in Komatsu).
B(n, m) = - Sum_{k=0..n-1} n!*B(k, m)/((n - k + m)!*k!) for n > 0 (see Lemma 2.1 in Komatsu).
B(n, m) = n!*Sum_{k=1..n} (-1)^k*Sum_{i_1+...+i_k=n; i_1,...,i_k>=1} Product_{j=1..k} 1/(i_j + m)! for n > 0 (see Theorem 2.2 in Komatsu).
B(n, m) = (-1)^n*n!*det(M(n, m)) where M(n, m) is the n X n Toeplitz matrix whose first row consists in 1/(m + 1)!, 1, 0, ..., 0 and whose first column consists in 1/(m + 1)!, 1/(m + 2)!, ..., 1/(m + n)! (see Theorem 2.3 in Komatsu).
B(1, m) = -1/(m + 1)! (see Theorem 2.4 in Komatsu).
B(n, m) = n!*Sum_{t_1+2*t_2+...+n*t_n=n} (t_1,...,t_n)!*(-1)^(t_1+…+t_n)*Product_{j=1..n} (1/(m + j)!)^t_j for n >= m >= 1 (see Theorem 2.7 in Komatsu).
(-1)^n/(n + m)! = det(M(n, m)) where M(n, m) is the n X n Toeplitz matrix whose first row consists in B(1, m), 1, 0, ..., 0 and whose first column consists in B(1, m), B(2, m)/2!, ..., B(n, m)/n! (see Theorem 2.8 in Komatsu).
Sum_{k=0..n} binomial(n, k)*B(k, m)*B(n-k, m) = - n!/(m^2*m!)*Sum_{l=0..n-1} ((m! - 1)/(m*m!))^(n-l-1)*(l*(m! - 1) + m)/l!*B(l, m) - (n - m)/m*B(n, m) for m > 0 (see Theorem 4.1 in Komatsu).
EXAMPLE
Array T(n, m):
n\m| 0 1 2 3 4 ...
---+--------------------------------------------
0 | 1 1 1 1 1 ...
1 | 1 2 6 24 120 ...
2 | 1 6 36 1440 7200 ...
3 | 1 1 180 11520 672000 ...
4 | 1 30 1080 2419200 60480000 ...
...
Related table of shifted Bernoulli numbers B(n, m):
1 1 1 1 1 ...
-1 -1/2 -1/6 -1/24 -1/120 ...
1 1/6 -1/36 -19/1440 -19/7200 ...
-1 0 1/180 -53/11520 -709/672000 ...
1 -1/30 11/1080 -3113/2419200 -28813/60480000 ...
...
MATHEMATICA
B[n_, m_]:=n!Coefficient[Series[x^m/(Exp[x]-Sum[x^k/k!, {k, 0, m}]+x^m), {x, 0, n}], x, n]; Table[Denominator[B[n-m, m]], {n, 0, 9}, {m, 0, n}]//Flatten
CROSSREFS
Cf. A000012 (1st column and 1st row), A000142 (2nd row), A027641, A027642 (2nd column), A141056, A164555, A176327, A226513 (high-order Fubini numbers), A338875, A338876.
Cf. A338873 (numerators).
Sequence in context: A199063 A140956 A166919 * A338876 A260238 A283795
KEYWORD
nonn,frac,tabl
AUTHOR
Stefano Spezia, Nov 13 2020
STATUS
approved