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 A128945 #8 Mar 26 2025 17:19:15
%S A128945 2,3,4,5,6,10,12,16,20,149,150,476,594,788,1574,1664,1691,6117,6242
%N A128945 Numbers n such that the greatest prime < 2^n is a twin prime member.
%C A128945 A014234(a(n)) is in A001097 (twin primes).
%e A128945 For n=5, 31 is the greatest prime < 2^5 and is a member of the twin prime pair 29, 31.
%t A128945 Select[Range[1700],AnyTrue[NextPrime[2^#,-1]+{2,-2},PrimeQ]&] (* The program generates the first 17 terms of the sequence. *) (* _Harvey P. Dale_, Mar 26 2025 *)
%o A128945 (PARI) g(n,b)=for(x=1,n,y=precprime(b^x);if(ispseudoprime(y-2),print1(x",")))
%K A128945 hard,more,nonn
%O A128945 1,1
%A A128945 _Cino Hilliard_, Apr 28 2007
%E A128945 Edited by and terms a(15)-a(17) from _Ray Chandler_, May 12 2007
%E A128945 a(18), a(19) _Donovan Johnson_, Feb 21 2008