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 A367647 #27 Jan 19 2024 21:31:39 %S A367647 1,1,2,1,4,2,1,3,4,1,2,3,2,4,2,9,1,1,6,2,3,2,7,3,5,2,6,1,6,7,10,1,3,4, %T A367647 2,4,5,1,2,5,1,2,3,8,1,7,1,2,2,3,5,4,7,11,3,4,2,3,1,2,10,1,4,9,1,2,6, %U A367647 1,4,15,4,6,2,5,8,1,2,3,4,1,3,2,3,5,8,3,5,2,4,7,2,5,1,3,12,1,2,2,4,7 %N A367647 Irregular triangle read by rows in which row n lists the positive values k such that there are no primes between k*n and k*(n + 1), or -1 if no such k exists. %e A367647 Triangle begins: %e A367647 1; %e A367647 1; %e A367647 1; %e A367647 2; %e A367647 1; %e A367647 4; %e A367647 2; %e A367647 1, 3, 4; %e A367647 1; %e A367647 2; %e A367647 3; %e A367647 2, 4; %e A367647 2, 9; %e A367647 1; %e A367647 1, 6; %e A367647 2, 3; %e A367647 2, 7; %e A367647 3, 5; %e A367647 2, 6; %e A367647 1, 6, 7, 10; %e A367647 1, 3, 4; %e A367647 2; %e A367647 4, 5; %e A367647 1, 2, 5; %e A367647 1, 2, 3, 8. %Y A367647 Cf. A068780, A047845, A110835, A278425. %K A367647 nonn,tabf,easy %O A367647 1,3 %A A367647 _Juri-Stepan Gerasimov_, Nov 25 2023