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 A110774 #6 Nov 14 2021 12:35:14 %S A110774 11,3,11,33,1111111,3333333333, %T A110774 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 %N A110774 Copies of 1 and 3 alternately such that every partial concatenation is a prime. %e A110774 11, 113, 11311, etc. are primes. %Y A110774 Cf. A110775, A110776, A110777, A110778, A112534, A110780, A110781, A110782, A110783, A110788, A110789. %K A110774 base,nonn %O A110774 1,1 %A A110774 _Amarnath Murthy_, Aug 12 2005 %E A110774 The next term is too large to include. %E A110774 Corrected and extended by _Joshua Zucker_, Jan 11 2006