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Where the prime race among 7k+1, ..., 7k+6 changes leader.
(Formerly M2101)
9

%I M2101 #26 Jul 26 2021 02:10:08

%S 2,17,131,227,733,829,929,997,1097,1123,1237,1277,1447,1487,1531,1627,

%T 1811,1907,1993,2141,2203,2267,2441,2677,2707,3209,3299,3433,3547,

%U 3853,4003,4021,4507,4679,4787,4931,5081,5113,7537,7577,7649,7759,7817,8039,8461,8543

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

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

%H T. D. Noe, <a href="/A007354/b007354.txt">Table of n, a(n) for n = 1..1000</a>

%H Robert G. Wilson v, <a href="/A005596/a005596.pdf">Letter to N. J. A. Sloane, Aug. 1993</a>

%o (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))};

%o primerace(7,8600) \\ _Hugo Pfoertner_, Jul 25 2021

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

%K nonn

%O 1,1

%A _N. J. A. Sloane_, _Mira Bernstein_, _Robert G. Wilson v_