A126025 - cp's OEIS frontend

A126025 Number of mappings f:{1,2,3,...,n} -> {1,2,3,...,n} such that gcd(f(x),f(y)) = f(gcd(x,y)) for all x,y in {1,2,3,...,n}.

n	a(n)
1	1
2	3
3	9
4	26
5	106
6	191
7	954
8	2427
9	8404
10	15945
11	111952
12	141117
13	1176623
14	2270566
15	4477947
16	10345290
17	104257447
18	145407966
19	1633452518
20	2517488363
21	5024167821
22	9148333241
23	120260250853

[1, 3, 9, 26, 106, 191, 954, 2427, 8404, 15945, 111952, 141117, 1176623, 2270566, 4477947, 10345290, 104257447, 145407966, 1633452518, 2517488363, 5024167821, 9148333241, 120260250853]

cp's OEIS Frontend

A126025 Number of mappings f:{1,2,3,...,n} -> {1,2,3,...,n} such that gcd(f(x),f(y)) = f(gcd(x,y)) for all x,y in {1,2,3,...,n}.

Table of values

List of values