A392295 Primes p such that Pi_{5,2}(p) + Pi_{5,3}(p) - Pi_{5,1}(p) - Pi_{5,4}(p) = -1, where Pi_{m,n}(p) denotes the number of primes q <= p with q == n (mod m).

2082927221, 2082927367, 2082927443, 2082927481, 2082928013, 2082928117, 2082928229, 2082940207, 2082940229, 2082940243, 2082940663, 2082940669, 2082940723, 2082940777, 2082940799, 2082940829, 2082940879, 2082940913, 2082940943, 2082940991, 2082941039, 2082941131, 2082941591, 2082943883

Offset

1,1

Comments

In general, assuming the strong form of the Riemann Hypothesis, if 0 < a, b < k are integers, gcd(a, k) = gcd(b, k) = 1, a is a quadratic residue and b is a quadratic nonresidue mod k, then Pi(k,b)(n) > Pi(k,a)(n) occurs more often than not. Pi(a,b)(x) denotes the number of primes in the arithmetic progression a*k + b less than or equal to x. This phenomenon is called "Chebyshev's bias". (See Wikipedia link and especially the links in A007350.)

Links

Jianing Song, Table of n, a(n) for n = 1..1090 (all terms up to the first region where Pi_{5,2}+Pi_{5,3}-Pi_{5,1}-Pi_{5,4} is negative)

Andrew Granville and Greg Martin, Prime number races, Amer. Math. Monthly, 113 (No. 1, 2006), 1-33.

Wikipedia, Chebyshev's bias

Prog

(PARI) my(i=0); forprime(p=2, 2083000000, i+=kronecker(5, p); if(i==1, print1(p, ", ")))

Crossrefs

Cf. prime indices of -1, 0, 1, 2, 3 in A321857: this sequence, A392296, A392297, A392298, A392299.

Sequence in context: A292546 A287593 A392296 * A216012 A096561 A096560

Adjacent sequences: A392292 A392293 A392294 * A392296 A392297 A392298

Keyword

nonn

Author

Jianing Song, Jan 08 2026

Status

approved