cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A338873 Array T(n, m) read by ascending antidiagonals: numerators of shifted Bernoulli numbers B(n, m) where m >= 0.

Original entry on oeis.org

1, -1, 1, 1, -1, 1, -1, 1, -1, 1, 1, 0, -1, -1, 1, -1, -1, 1, -19, -1, 1, 1, 0, 11, -53, -19, -1, 1, -1, 1, 43, -3113, -709, -713, -1, 1, 1, 0, -289, 349, -28813, -63367, -629, -1, 1, -1, -1, -313, 174947, -46721, -34877471, -351541, -1493, -1, 1, 1, 0, -581, 704101, -20744051, -2449743889, -176710589, -18054401, -36287, -1, 1
Offset: 0

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Author

Stefano Spezia, Nov 13 2020

Keywords

Examples

			Array T(n, m):
n\m|   0       1       2       3       4 ...
---+------------------------------------
0  |   1       1       1       1       1 ...
1  |  -1      -1      -1      -1      -1 ...
2  |   1       1      -1     -19     -19 ...
3  |  -1       0       1     -53    -709 ...
4  |   1      -1      11   -3113  -28813 ...
...
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 ...
  ...
		

Crossrefs

Cf. A000012 (1st row), A027641 (2nd column), A027642, A033999 (1st column), A141056, A164555, A176327, A226513 (high-order Fubini numbers), A338875, A338876.
Cf. A338874 (denominators).

Programs

  • 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[Numerator[B[n-m,m]],{n,0,10},{m,0,n}]//Flatten

Formula

T(n, m) = numerator(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).