A143195 Triangle read by rows: row n gives coefficients of expansion of q-reduced tangent number d_{n}(q) in powers of q.

1, 1, 2, 2, 5, 12, 12, 5, 14, 56, 110, 136, 110, 56, 14, 42, 240, 702, 1382, 2020, 2284, 2020, 1382, 702, 240, 42, 132, 990, 3850, 10274, 20986, 34690, 47846, 55984, 55984, 47846, 34690, 20986, 10274, 3850, 990, 132, 429, 4004, 19448, 65221, 169052, 359517, 650225, 1023273, 1422297

Offset

0,3

Comments

d_n(q) = T_{2n+1}(q)/((1+q)(1+q^2)...(1+q^n)) (see A143194).

Links

Table of n, a(n) for n=0..50.

Dominique Foata, Guo-Niu Han, Doubloons and new q-tangent numbers, Quart. J. Math. 62 (2) (2011) 417-432

Example

Triangle begins:
1
1
2 2
5 12 12 5
14 56 110 136 110 56 14
...

Crossrefs

Sequence in context: A208581 A233357 A248664 * A192799 A181354 A085289

Adjacent sequences: A143192 A143193 A143194 * A143196 A143197 A143198

Keyword

nonn,tabf

Author

N. J. A. Sloane, Oct 25 2008

Status

approved