A030267 - cp's OEIS frontend

A030267 Compose the natural numbers with themselves, A(x) = B(B(x)) where B(x) = x/(1-x)^2 is the generating function for natural numbers.

n	a(n)
1	1
2	4
3	14
4	46
5	145
6	444
7	1331
8	3926
9	11434
10	32960
11	94211
12	267384
13	754309
14	2116936
15	5914310
16	16458034
17	45638101
18	126159156
19	347769719
20	956238170
21	2623278946
22	7181512964
23	19622668679
24	53522804976
25	145753273225
26	396323283724
27	1076167858046
28	2918447861686

[1, 4, 14, 46, 145, 444, 1331, 3926, 11434, 32960, 94211, 267384, 754309, 2116936, 5914310, 16458034, 45638101, 126159156, 347769719, 956238170, 2623278946, 7181512964, 19622668679, 53522804976, 145753273225, 396323283724, 1076167858046, 2918447861686]

cp's OEIS Frontend

A030267 Compose the natural numbers with themselves, A(x) = B(B(x)) where B(x) = x/(1-x)^2 is the generating function for natural numbers.

Table of values

List of values