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 A337423 #8 Aug 28 2020 11:04:18 %S A337423 7,37,67,337,607,3037,15187,27337,49207,683437,0,131835937,659179687, %T A337423 19929037,35872267,228881835937,2491129687,0,0,311391210937, %U A337423 12013549804687,0,235357947067,1176789735337,0,10591107618037,52955538090187,5675104819335937,608185958862304687 %N A337423 a(n) is the least prime of the form (3^j*5^k - 1)/2, j > 0, k > 0, j + k = n. a(n) = 0 if no such prime exists. %Y A337423 Cf. A093625, A076481, A337424, A337425, A337426. %K A337423 nonn %O A337423 2,1 %A A337423 _Hugo Pfoertner_, Aug 27 2020