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 A331138 #9 Jul 18 2021 07:05:54 %S A331138 4,7,5,12,7,6,18,10,8,7,26,14,11,9,8,35,19,14,11,10,9,45 %N A331138 Triangle read by rows: T(n,k) (n>=3, k>=1) = length of shortest code realizing a synch-set S(n,k). %D A331138 Simmons, G. J., Synch sets: A variant of difference sets. Report No. SLA-74-5068; CONF-740217-1. Sandia Labs., Albuquerque, N. Mex.(USA), 1974. Also in Proceedings of the Fifth Southeastern Conference on Combinatorics, Graph Theory and Computing (Florida Atlantic Univ., Boca Raton, Fla., 1974), pp. 625-645. Congressus Numerantium, No. X, Utilitas Math., Winnipeg, Man., 1974. MR0357160 (50 #9628) %e A331138 Triangle begins: %e A331138 4; %e A331138 7, 5; %e A331138 12, 7, 6; %e A331138 18, 10, 8, 7; %e A331138 26, 14, 11, 9, 8; %e A331138 35, 19, 14, 11, 10, 9; %e A331138 45, ... %e A331138 ... %Y A331138 The first column appears to be A227590. %K A331138 nonn,tabl,more %O A331138 3,1 %A A331138 _N. J. A. Sloane_, Jan 12 2020