A231291 - cp's OEIS frontend

A231291 G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (1 + kx) / (1 - x - kx^2).

n	a(n)
0	1
1	1
2	3
3	9
4	29
5	99
6	355
7	1333
8	5213
9	21163
10	88899
11	385413
12	1720637
13	7894827
14	37166563
15	179254501
16	884548253
17	4460597131
18	22962705027
19	120557527941
20	644952640253
21	3512995320939
22	19468234666531
23	109694091843109
24	628027149163613
25	3651429293510731
26	21547912967252163

[1, 1, 3, 9, 29, 99, 355, 1333, 5213, 21163, 88899, 385413, 1720637, 7894827, 37166563, 179254501, 884548253, 4460597131, 22962705027, 120557527941, 644952640253, 3512995320939, 19468234666531, 109694091843109, 628027149163613, 3651429293510731, 21547912967252163]

cp's OEIS Frontend

A231291 G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (1 + kx) / (1 - x - kx^2).

Table of values

List of values

cp's OEIS Frontend

A231291 G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (1 + k*x) / (1 - x - k*x^2).

Table of values

List of values

A231291 G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (1 + kx) / (1 - x - kx^2).