A350084 a(n) = ord(2,A006935(n)/2), where ord(k,m) is the multiplicative order of k modulo m.

1, 261, 165, 275, 13425, 1485, 1305, 32085, 825, 3465, 2093, 3135, 495, 495, 261, 847, 9405, 552189, 198561, 261, 579261, 2475, 6237, 166725, 111111, 3393, 3565, 25245, 18585, 4437, 891891, 309455, 37125, 4833, 2301585, 14355, 11781, 3315, 915, 84975, 35259

Offset: 1

Author

Jianing Song, Dec 12 2021

Keywords

• nonn

Comments

List of ord(2,k) where k ranges over the odd numbers such that 2^(2*k-1) == 1 (mod k).

Examples

			A006935(2) = 161038, so a(2) = ord(2,161038/2) = 261.
A006935(3) = 215326, so a(3) = ord(2,215326/2) = 165.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1319

Crossrefs

Cf. A006935, A347906, A350083, A306413, A306414.

Programs

PARI

list(lim) = my(v=[],d); forstep(k=1, lim, 2, if((2*k-1)%(d=znorder(Mod(2,k)))==0, v=concat(v,d))); v \\ gives a(n) for A347906(n) <= lim

Formula

a(n) = ord(2,A347906(n)) = (A006935(n) - 1) / A350083(n).