A007354 Where the prime race among 7k+1, ..., 7k+6 changes leader.

2, 17, 131, 227, 733, 829, 929, 997, 1097, 1123, 1237, 1277, 1447, 1487, 1531, 1627, 1811, 1907, 1993, 2141, 2203, 2267, 2441, 2677, 2707, 3209, 3299, 3433, 3547, 3853, 4003, 4021, 4507, 4679, 4787, 4931, 5081, 5113, 7537, 7577, 7649, 7759, 7817, 8039, 8461, 8543

Offset: 1

Author

N. J. A. Sloane, Mira Bernstein, Robert G. Wilson v

Keywords

• nonn

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000
• Robert G. Wilson v, Letter to N. J. A. Sloane, Aug. 1993

Crossrefs

Cf. A007352, A007350, A007353, A007354, A297406, A297407, A297408, A297410, A297411.

Programs

PARI

primerace(mod,limit)={my(v=vector(mod), vm=0, ivm=0, imv); forprime(p=2, limit, my(m=p%mod); v[m+1]++;  v[m+1]++; my(mv=vecmax(v, &imv)); if(mv>vm, if(imv!=ivm, print1(p, ", "); ivm=imv); vm=mv))};
primerace(7,8600) \\ Hugo Pfoertner, Jul 25 2021