OFFSET
1,2
COMMENTS
For any integers n and k, the ratio k^(2n)*(k^(2n)-1)*B(2n)/(2n) is always an integer.
Row 1 is A002415 = 4-D pyramidal numbers,
Row 2 and following rows are not in the OEIS,
Column 1 is A000182 = Tangent numbers,
Column 2 is A047681,
Column 3 is A047682,
Column 4 is A047683,
Column 5 and following columns are not in the OEIS.
LINKS
EXAMPLE
Array begins:
1, 6, 20, 50, 105, ...
2, 54, 544, 3250, 13986, ...
16, 2106, 66560, 968750, 8637840, ...
272, 179334, 17895424, 635781250, 11754617616, ...
7936, 26414586, 8329625600, 722480468750, 27698169542400, ...
etc.
MATHEMATICA
nmax = 8; t[n_, k_] := k^(2*n)*(k^(2*n)-1)*BernoulliB[2*n]/(2*n); Table[t[n-k+2, k] // Abs, {n, 1, nmax}, {k, 2, n+1}] // Flatten
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Jean-François Alcover, Apr 16 2014
STATUS
approved