A258797 - cp's OEIS frontend

A258797 a(n) = [x^n] Product_{k=1..n} (1+x^k)^2 / x^k.

n	a(n)
0	1
1	1
2	2
3	6
4	16
5	51
6	166
7	554
8	1896
9	6595
10	23212
11	82582
12	296393
13	1071738
14	3900696
15	14278074
16	52526972
17	194108087
18	720197524
19	2681854490
20	10019539112
21	37545876368
22	141080872362
23	531457445806
24	2006678785762
25	7593123695669
26	28789152013570
27	109356019134584

[1, 1, 2, 6, 16, 51, 166, 554, 1896, 6595, 23212, 82582, 296393, 1071738, 3900696, 14278074, 52526972, 194108087, 720197524, 2681854490, 10019539112, 37545876368, 141080872362, 531457445806, 2006678785762, 7593123695669, 28789152013570, 109356019134584]

cp's OEIS Frontend

A258797 a(n) = [x^n] Product_{k=1..n} (1+x^k)^2 / x^k.

Table of values

List of values