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 A036339 #9 Oct 26 2020 17:15:46 %S A036339 467,941,13681,14461,21787,22171,22369,24049,24151,25457,29333,37397, %T A036339 41221,42467,43481,46511,48023,54133,56681,68699,75883,85081,101341, %U A036339 103511,117443,120193,126199,137363,144323,145133,158791,175853,181891,183797 %N A036339 Concatenation of prime p and nextprime(p) is prime -> cycles of 2 steps possible. %H A036339 C. Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_029.htm">Details of procedure</a> %Y A036339 Cf. A030459, A034592, A036340, A036341. %K A036339 nonn,base %O A036339 1,1 %A A036339 _Patrick De Geest_, Dec 15 1998 %E A036339 Offset corrected and missing 181891 inserted by _Sean A. Irvine_, Oct 26 2020