A308475 - cp's OEIS frontend

A308475 a(1) = 1; a(n) = Sum_{k=1..n-1, gcd(n,k) = 1} binomial(n,k)*a(k).

n	a(n)
1	1
2	2
3	9
4	40
5	315
6	1896
7	21651
8	191360
9	2546487
10	28064080
11	488517183
12	5879603280
13	124673371719
14	1928346159572
15	42684093159480
16	754925802649360
17	20289814995554811
18	366300418631427144
19	11352374441063693655
20	250187625076714423520
21	7774760839170720287739

[1, 2, 9, 40, 315, 1896, 21651, 191360, 2546487, 28064080, 488517183, 5879603280, 124673371719, 1928346159572, 42684093159480, 754925802649360, 20289814995554811, 366300418631427144, 11352374441063693655, 250187625076714423520, 7774760839170720287739]

cp's OEIS Frontend

A308475 a(1) = 1; a(n) = Sum_{k=1..n-1, gcd(n,k) = 1} binomial(n,k)*a(k).

Table of values

List of values