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 A128817 #9 Jun 30 2024 03:29:43
%S A128817 7,19,81349,3335149,196773559,13970922409,150983758430839
%N A128817 Primes which are 4 greater than the product of lesser twin primes.
%C A128817 Also primes which are 4 greater than the terms of A097489, where A097489 = product of first n terms of A001359 and A001359 = Lesser of twin primes.
%C A128817 a(8) = A097489(547) + 4 = 4.247...*10^2176. - _Amiram Eldar_, Jun 30 2024
%F A128817 Define twinl#(n)as the product of the first n lesser twin primes. Then if twinl#+4 is prime, list it.
%e A128817 twinl#(2) = 3*5=15. 15+4 = 19 prime and the second term in the table.
%o A128817 (PARI) twinl(n) = /* The n-th lower twin prime */ { local(c,x); c=0; x=1; while(c<n, if(isprime(prime(x)+2),c++); x++; ); return(prime(x-1)); }
%o A128817 twiprimesl(n,a) = { local(pr,x,y,j); for(j=1,n, pr=1; for(x=1,j, pr*=twinl(x); ); y=pr+a; if(ispseudoprime(y), print1(y",") ) ); }
%Y A128817 Cf. A001359, A097489.
%K A128817 nonn
%O A128817 1,1
%A A128817 _Cino Hilliard_, May 08 2007