This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A317851 #15 Aug 11 2018 15:36:14
%S A317851 31,43,61,67,73,79,97,103,107,113,127,131,137,151,163,167,173,181,191,
%T A317851 193,197,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,
%U A317851 293,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,401,409,419,421
%N A317851 Primes p such that A090086(p+1) < p.
%C A317851 Theorem: if n-1 is composite, then A090086(n) < n.
%C A317851 The inverse theorem is false iff n = p+1 for primes p in this sequence.
%C A317851 Conjecture: the sequence contains all sufficiently large primes. Probably all primes except 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 37, 41, 47, 53, 59, 71, 83, 89, 101, 109, 139, 149, 157, 179, 199, 307, 461, and 571.
%e A317851 The prime 31 is a term, since A090086(31+1) = 25 < 31.
%o A317851 (PARI) b(n) = {forcomposite(k=2, , if (Mod(n, k)^(k-1) == 1, return (k)); ); }
%o A317851 isok(p) = isprime(p) && (b(p+1) < p); \\ _Michel Marcus_, Aug 09 2018
%Y A317851 Cf. A000040, A090086.
%K A317851 nonn
%O A317851 1,1
%A A317851 _Thomas Ordowski_, Aug 09 2018
%E A317851 Corrected and extended by _Michel Marcus_, Aug 09 2018