A242573 - cp's OEIS frontend

A242573 a(n) = [x^n] G(n-1,x) where G(n,x) is the n-th iteration of G(1,x) = x/(1-x+x^2), so that G(n,x) = G(n-1, G(1,x)) with G(0,x)=x.

n	a(n)
1	1
2	1
3	2
4	6
5	24
6	120
7	702
8	4445
9	27812
10	187911
11	4154105
12	226545132
13	11811552612
14	567839904255
15	26530164469576
16	1244353584654296
17	59633342751369016
18	2947881116272213508
19	151083714566902161495
20	8048911065786420441543
21	446230730213409483222040

[1, 1, 2, 6, 24, 120, 702, 4445, 27812, 187911, 4154105, 226545132, 11811552612, 567839904255, 26530164469576, 1244353584654296, 59633342751369016, 2947881116272213508, 151083714566902161495, 8048911065786420441543, 446230730213409483222040]

cp's OEIS Frontend

A242573 a(n) = [x^n] G(n-1,x) where G(n,x) is the n-th iteration of G(1,x) = x/(1-x+x^2), so that G(n,x) = G(n-1, G(1,x)) with G(0,x)=x.

Table of values

List of values