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 A323713 #25 Feb 13 2019 04:57:00 %S A323713 2,3,3,5,61,1171241,1197631,25451791,25451791,9560914721,9560914721, %T A323713 860964705721,185133795875771 %N A323713 a(n) = beginning of a run of at least n primes when x -> 3*x - 2 is iterated. %C A323713 For n > 4, a(n) == 1 (mod 10). %e A323713 a(4) = 5 because 5 is the beginning of 4 primes in succession: 5, 3*5 - 2 = 13 is prime, 3*13 - 2 = 37 is prime, 3*37 - 2 = 109 is prime. %t A323713 c[p_] := Block[{k=1, q = 3 p - 2}, While[PrimeQ[q], q = 3 q - 2; k++]; k]; a[n_] := Block[{p=2}, While[c[p] < n, p = NextPrime[p]]; p]; Array[a, 7] %o A323713 (PARI) a(n)={x=1;k=1;while(k==1,m=0;y=x;while(isprime(y),m++;if(m==n,k=x);y=3*y-2);x++);k;} %Y A323713 Cf. A083388. %K A323713 nonn,more %O A323713 1,1 %A A323713 _Jinyuan Wang_, Jan 25 2019 %E A323713 a(8)-a(11) from _Daniel Suteu_, Jan 27 2019 %E A323713 a(12)-a(13) from _Giovanni Resta_, Feb 04 2019