A170822 Let p = n-th prime; a(n) = (p-1)/(order of A170821(n) mod p).

1, 3, 2, 2, 1, 1, 2, 1, 1, 12, 1, 1, 2, 1, 2, 4, 1, 14, 2, 1, 2, 1, 2, 1, 1, 2, 2, 1, 1, 10, 1, 3, 1, 1, 4, 9, 2, 1, 2, 18, 2, 16, 1, 1, 1, 1, 2, 2, 1, 2, 6, 2, 1, 2, 1, 1, 2, 1, 1, 1, 3, 10, 12, 1, 1, 42, 2, 12, 1, 2, 1, 4, 27, 2, 1, 4, 1, 6, 2, 6, 10, 4, 3, 2, 1, 2, 1, 1, 2, 2, 1, 2, 3, 2, 1, 5

Offset

3,2

Links

Table of n, a(n) for n=3..98.

I. Anderson and D. A. Preece, Combinatorially fruitful properties of 3*2^(-1) and 3*2^(-2) modulo p, Discr. Math., 310 (2010), 312-324.

Example

n=3: p=5, A170821(n)=2, order of 2 mod 5 = 4, (5-1)/4 = 1 = a(3).

Prog

(PARI) f(n) = my(p=prime(n), k=0); while(Mod(4*k, p) != 3, k++); k; \\ A170821
a(n) = my(p=prime(n)); (p-1)/znorder(Mod(f(n), p)); \\ Michel Marcus, Dec 04 2018

Crossrefs

Cf. A001917, A170820, A170821.

Sequence in context: A328330 A214878 A086138 * A054546 A065310 A226352

Adjacent sequences: A170819 A170820 A170821 * A170823 A170824 A170825

Keyword

nonn

Author

N. J. A. Sloane, Dec 24 2009

Status

approved