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A156902 Primes p such that there is no multiple of (the order of p among the primes) between p and q, where q is the smallest prime > p. 0

%I #10 Jan 22 2019 22:53:21

%S 11,13,17,19,37,41,43,47,53,59,61,67,71,73,79,83,101,103,107,109,127,

%T 131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,

%U 227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313

%N Primes p such that there is no multiple of (the order of p among the primes) between p and q, where q is the smallest prime > p.

%C If pi(p) is the order of the prime p, then p is included in the sequence if pi(p)*ceiling(p/pi(p)) > the (pi(p)+1)th prime.

%C The sequence of primes not in the list is less dense: 2, 3, 5, 7, 23, 29, 31, 89, 97, 113, 317, 331, 337, 349, 353, 359, 997, 1069, 1091, 1109, 1117, 1123, 1129, 3049, 3061, 3067, 3079, 3083, 3089, ... - _R. J. Mathar_, Feb 21 2009

%e 37 is the 12th prime. 41 is the 13th prime. Since there is no multiple of 12 between 37 and 41, then 37 is included in the sequence.

%p for n from 1 to 300 do p := ithprime(n) ; q := nextprime(p) ; if n*floor(q/n) < p then printf("%d,",p) ; fi; od: # _R. J. Mathar_, Feb 21 2009

%Y Cf. A068902.

%K nonn

%O 1,1

%A _Leroy Quet_, Feb 17 2009

%E Extended by _R. J. Mathar_, Feb 21 2009

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Last modified April 25 05:18 EDT 2024. Contains 371964 sequences. (Running on oeis4.)