A371687 - cp's OEIS frontend

A371687 Triangle read by rows: T(n, k) = (-1)^(n-k) * (2n + 1)! [y^(2k)] [x^(2n+1)] arctan(sec(xy)tanh(x)).

n	a(n)
0	1
1	4
2	3
3	80
4	80
5	25
6	3904
7	5376
8	2660
9	427
10	354560
11	626688
12	433440
13	131712
14	12465
15	51733504
16	111738880
17	99242880
18	43804992
19	9021540
20	555731
21	11070525440
22	28258074624
23	30647302400
24	17666508288
25	5509286640
26	816337808
27	35135945

[1, 4, 3, 80, 80, 25, 3904, 5376, 2660, 427, 354560, 626688, 433440, 131712, 12465, 51733504, 111738880, 99242880, 43804992, 9021540, 555731, 11070525440, 28258074624, 30647302400, 17666508288, 5509286640, 816337808, 35135945]

cp's OEIS Frontend

A371687 Triangle read by rows: T(n, k) = (-1)^(n-k) * (2n + 1)! [y^(2k)] [x^(2n+1)] arctan(sec(xy)tanh(x)).

Table of values

List of values

cp's OEIS Frontend

A371687 Triangle read by rows: T(n, k) = (-1)^(n-k) * (2*n + 1)! * [y^(2*k)] [x^(2*n+1)] arctan(sec(x*y)*tanh(x)).

Table of values

List of values

A371687 Triangle read by rows: T(n, k) = (-1)^(n-k) * (2n + 1)! [y^(2k)] [x^(2n+1)] arctan(sec(xy)tanh(x)).