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 A110790 #15 Mar 16 2025 23:51:54 %S A110790 3,1,3,111111111111111,33333, %T A110790 111111111111111111111111111111111111111111111111111111111111111111111111111111111111111, %U A110790 3333,111111111111111111111111111,33333 %N A110790 Copies of 3 and 1 alternately such that every partial concatenation is a prime. %C A110790 The next term has 168 digits. - _Charles R Greathouse IV_, Sep 29 2008 %e A110790 3, 31, 313, 313111111111111111, ... are all prime. %Y A110790 Cf. A110791 (digit lengths) %Y A110790 Other digits: A110774, A110776, A110778, A110780, A110782, A110788. %K A110790 base,easy,nonn %O A110790 1,1 %A A110790 _Amarnath Murthy_, Aug 13 2005 %E A110790 a(6)-a(9) from_Charles R Greathouse IV_, Sep 29 2008