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 A375234 #22 Aug 14 2024 10:04:43 %S A375234 1331,131337,113337,13139731,113113337,11933371,1313717979, %T A375234 113149971311,119314713911,1119737379,131313131397,113107709179991, %U A375234 1193100990013911,111971414339313,111119333337 %N A375234 Square array T(n,k), n>1 and k>1, read by antidiagonals in ascending order, giving the smallest n*k-digit number that, if arranged in an n X k matrix, forms a k-digit emirp (A006567) in each row and an n-digit emirp in each column, or -1 if no such number exists. %e A375234 T(3,2) = 131337 is the smallest 3*2-digit that if arranged in a 3 X 2 matrix yields in each row and column an emirp, i.e., %e A375234 13 %e A375234 13 %e A375234 37 %e A375234 -> 13 (2 times), 37 (1 times), 113 (1 time), 337 (1 time) are all emirps. %e A375234 Table begins (upper left corner = T(2,2)): %e A375234 1331 113337 11933371 ... %e A375234 131337 113113337 119314713911 ... %e A375234 13139731 113149971311 1193100990013911 ... %e A375234 ... ... ... ... %Y A375234 Cf. A006567, A224164, A375171. %K A375234 nonn,base,tabl,more %O A375234 2,1 %A A375234 _Jean-Marc Rebert_, Aug 06 2024