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 A224398 #12 Jul 06 2024 19:45:15 %S A224398 2,3,5,7,1117,1171,179991179,191797919,337353739,733353337, %T A224398 1193100992213191,1193120192093911,1193900112293191,1193902910213911, %U A224398 1733922710213719,1933913317893391,1933983337193191,3191100999231193,3191949710331913,3371722912019173 %N A224398 Prime numbers with m^2 digits that, if arranged in an m X m matrix, form m-digit reversible primes in each row, column, and in the two main diagonals. %C A224398 Subsequence of A224164, in which only the main diagonal is requested to be a reversible prime. Suggested by _Charles R Greathouse IV_. %C A224398 The smallest terms with 4, 9, 16, 25 and 36 digits are 1117, 179991179, 1193100992213191, 1119710007705077000179111 and 111119100049100049928141172283919913. %H A224398 Giovanni Resta, <a href="/A224398/b224398.txt">Table of n, a(n) for n = 1..10000</a> %e A224398 When the digits of the prime p = 3391382115599173 are arranged in a 4 X 4 matrix: %e A224398 3391 %e A224398 3821 %e A224398 1559 %e A224398 9173 %e A224398 the rows, the columns and the two main diagonals are 4-digit reversible primes, so p is in the sequence. %Y A224398 Cf. A224164. %K A224398 nonn,base %O A224398 1,1 %A A224398 _Giovanni Resta_, Apr 05 2013