A361462 a(n) = A135506(n) mod 4.

2, 1, 2, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1

Offset: 1

Author

Antti Karttunen, Mar 13 2023

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537

Crossrefs

Cf. A010873, A135506, A361463, A361464 (positions of 3's).

Programs

PARI

up_to = 65537;
A135506list(up_to_n) = { my(v=vector(up_to), x1=1, x2); for(n=2, 1+up_to_n, x2 = x1+lcm(x1, n); v[n-1] = (x2/x1)-1; x1=x2); (v); };
v135506 = A135506list(up_to);
A135506(n) = v135506[n];
A361462(n) = (A135506(n)%4);

Formula

a(n) = A010873(A135506(n)).