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A350083
a(n) = (A006935(n) - 1) / ord(2,A006935(n)/2), where ord(k,m) is the multiplicative order of k modulo m.
2
1, 617, 1305, 9339, 225, 5297, 6985, 1549, 174233, 46549, 93701, 66879, 431087, 593887, 1288921, 446275, 43685, 1205, 3361, 2577225, 1313, 430739, 177301, 8541, 13067, 474525, 561301, 84725, 158873, 725725, 3851, 14019, 128861, 1090301, 2529, 430667, 541673
OFFSET
1,2
COMMENTS
List of (2*k-1) / ord(2,k) where k ranges over the odd numbers such that 2^(2*k-1) == 1 (mod k).
LINKS
FORMULA
a(n) = (2*A347906(n) - 1) / ord(2,A347906(n)) = (A006935(n) - 1) / A350084(n).
EXAMPLE
A006935(2) = 161038, so a(2) = (161038 - 1) / ord(2,161038/2) = 617.
A006935(3) = 215326, so a(3) = (215326 - 1) / ord(2,215326/2) = 1305.
PROG
(PARI) list(lim) = my(v=[], d); forstep(k=1, lim, 2, if((2*k-1)%(d=znorder(Mod(2, k)))==0, v=concat(v, (2*k-1)/d))); v \\ gives a(n) for A347906(n) <= lim
CROSSREFS
KEYWORD
nonn
AUTHOR
Jianing Song, Dec 12 2021
STATUS
approved