A194972 - cp's OEIS frontend

A194972 a(n) equals the coefficient of x^n in the (2*n-1)-th iteration of x+x^2 for n>=1.

n	a(n)
1	1
2	3
3	20
4	231
5	3864
6	85140
7	2332616
8	76485227
9	2921536088
10	127421864328
11	6248486040840
12	340321635330534
13	20383240346962440
14	1331538898625750100
15	94216429100347571448
16	7178425650032302557691
17	585936966156456139931584
18	51011156414845408925712816

[1, 3, 20, 231, 3864, 85140, 2332616, 76485227, 2921536088, 127421864328, 6248486040840, 340321635330534, 20383240346962440, 1331538898625750100, 94216429100347571448, 7178425650032302557691, 585936966156456139931584, 51011156414845408925712816]

cp's OEIS Frontend

A194972 a(n) equals the coefficient of x^n in the (2*n-1)-th iteration of x+x^2 for n>=1.

Table of values

List of values