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 A128946 #14 Jul 27 2024 15:37:08 %S A128946 1,5,14,406,1118,4934 %N A128946 Numbers n such that the largest prime < 10^n is a twin prime member. %C A128946 A003618(a(n)) is in A001097 (Twin primes). %e A128946 For n=1, 10^1 = 10. 7, the greatest prime < 10, is a member of the twin prime pair 5,7. %t A128946 Select[Range[410],PrimeQ[NextPrime[10^#,-1]-2]&] (* The program generates the first four terms of the sequence. *) (* _Harvey P. Dale_, Jul 26 2024 *) %o A128946 (PARI) g(n)=for(x=1,n,y=precprime(10^x);if(ispseudoprime(y-2),print1(x","))) %K A128946 hard,more,nonn %O A128946 1,2 %A A128946 _Cino Hilliard_, Apr 28 2007 %E A128946 Edited by _Ray Chandler_, May 12 2007 %E A128946 a(5), a(6) from _Donovan Johnson_, Feb 21 2008