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 A133387 #10 Jan 03 2024 13:25:07
%S A133387 3,7,13,19,23,31,37,43,47,53,61,67,73,79,83,89,97,103,109,113,113,127,
%T A133387 131,139,139,151,157,163,167,173,181,181,193,199,199,211,211,223,229,
%U A133387 233,241,241,251,257,263,271,277,283,283,293,293,307,313,317,317,331
%N A133387 Greatest prime p such that 6*n-p is prime.
%H A133387 Nathaniel Johnston, <a href="/A133387/b133387.txt">Table of n, a(n) for n = 1..10000</a>
%p A133387 A133387 := proc(n) local p: p:=prevprime(6*n): while(not isprime(6*n-p))do p:=prevprime(p): od: return p: end: seq(A133387(n),n=1..100); # _Nathaniel Johnston_, Jun 25 2011
%t A133387 gpp[n_]:=Module[{p=NextPrime[6n,-1]},While[!PrimeQ[6n-p],p=NextPrime[ p,-1]];p]; Array[ gpp,60] (* _Harvey P. Dale_, Jan 03 2024 *)
%K A133387 nonn,easy
%O A133387 1,1
%A A133387 _Pierre CAMI_, Nov 23 2007