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 A038680 #13 Jul 08 2025 22:25:09 %S A038680 13,17,23,37,43,47,53,67,73,83,97,103,107,113,127,131,137,157,163,167, %T A038680 173,179,193,197,211,223,227,229,233,241,257,263,271,277,283,293,307, %U A038680 311,313,317,331,337,347,353,359,367,373,379,383,389,397 %N A038680 Primes ending in a (different) prime. %H A038680 Reinhard Zumkeller, <a href="/A038680/b038680.txt">Table of n, a(n) for n = 1..10000</a> %t A038680 ds[n_] := NestWhileList[FromDigits[Rest[IntegerDigits[#]]] &, n, # > 9 &]; Select[Prime[Range[5, 80]], Or @@ PrimeQ /@ Rest[ds[#]] &] (* _Jayanta Basu_, Jul 10 2013 *) %o A038680 (Haskell) %o A038680 import Data.List (tails) %o A038680 a038680 n = a038680_list !! (n-1) %o A038680 a038680_list = filter (any ((== 1) . a010051. read) . %o A038680 init . tail . tails . show) a000040_list %o A038680 -- _Reinhard Zumkeller_, Jul 10 2013 %Y A038680 Cf. A033664, A010051, A000040. %K A038680 nonn,base,easy %O A038680 1,1 %A A038680 _N. J. A. Sloane_ %E A038680 Missing a(19)=163 added by _Jayanta Basu_