A251688 - cp's OEIS frontend

A251688 G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2n} T(n,k)^2 x^k] / A(x)^n * x^n/n ), where T(n,k) is the coefficient of x^k in (1+2x)^n(1+3*x)^n.

n	a(n)
0	1
1	1
2	25
3	61
4	336
5	1200
6	3600
7	13500
8	32400
9	118800
10	259200
11	939600
12	1944000
13	6998400
14	13996800
15	50155200
16	97977600
17	349920000
18	671846400
19	2393452800
20	4534963200
21	16124313600
22	30233088000
23	107327462400
24	199538380800
25	707454259200
26	1306069401600
27	4625662464000
28	8489451110400

[1, 1, 25, 61, 336, 1200, 3600, 13500, 32400, 118800, 259200, 939600, 1944000, 6998400, 13996800, 50155200, 97977600, 349920000, 671846400, 2393452800, 4534963200, 16124313600, 30233088000, 107327462400, 199538380800, 707454259200, 1306069401600, 4625662464000, 8489451110400]

cp's OEIS Frontend

A251688 G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2n} T(n,k)^2 x^k] / A(x)^n * x^n/n ), where T(n,k) is the coefficient of x^k in (1+2x)^n(1+3*x)^n.

Table of values

List of values

cp's OEIS Frontend

A251688 G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} T(n,k)^2 * x^k] / A(x)^n * x^n/n ), where T(n,k) is the coefficient of x^k in (1+2*x)^n*(1+3*x)^n.

Table of values

List of values

A251688 G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2n} T(n,k)^2 x^k] / A(x)^n * x^n/n ), where T(n,k) is the coefficient of x^k in (1+2x)^n(1+3*x)^n.