A309587 Primes p with 2 zeros in a fundamental period of A006190 mod p.

7, 11, 17, 19, 31, 47, 59, 67, 71, 83, 113, 151, 163, 167, 223, 227, 239, 257, 271, 307, 313, 331, 337, 359, 379, 383, 431, 463, 479, 487, 499, 521, 587, 601, 619, 631, 641, 643, 673, 683, 691, 739, 743, 787, 809, 811, 827, 839, 863, 947, 967, 983

Offset

1,1

Comments

Primes p such that A322906(p) = 2.

For p > 2, p is in this sequence if and only if 8 divides A175182(p), and if and only if 4 divides A322907(p). For a proof of the equivalence between A322906(p) = 2 and 4 dividing A322907(p), see Section 2 of my link below.

This sequence contains all primes congruent to 7, 11, 15, 19, 31, 47 modulo 52. This corresponds to case (2) for k = 11 in the Conclusion of Section 1 of my link below.

Conjecturely, this sequence has density 1/3 in the primes. [Comment rewritten by Jianing Song, Jun 16 2024 and Jun 25 2024]

References

Ballot, Christian. "Prime Factors of Fibonacci-Related Recurrences." The Fibonacci Quarterly 63.2 (2025): 178-206.

Links

Jianing Song, Table of n, a(n) for n = 1..1200

Jianing Song, Entry points and periods of Lucas sequences

Prog

(PARI) forprime(p=2, 1000, if(A322906(p)==2, print1(p, ", ")))

Crossrefs

Cf. A006190, A175182, A322907.

For a list of sequences related to the numbers of zeros in a fundamental period of {x(n)}, where {x(n)} is a sequence defined by x(0) = 0, x(1) = 1, x(n+2) = m*x(n+1) + x(n), see A053032.

Sequence in context: A296926 A063639 A230223 * A386127 A339954 A386136

Adjacent sequences: A309584 A309585 A309586 * A309588 A309589 A309590

Keyword

nonn

Author

Jianing Song, Aug 10 2019

Status

approved