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 A069791 #15 Aug 28 2025 04:03:20 %S A069791 1021,1031,1033,1039,1051,1117,1171,1193,1231,1237,1291,1297,1319, %T A069791 1373,1433,1439,1471,1531,1597,1613,1619,1733,1831,1973,1979,2027, %U A069791 2029,2039,2053,2111,2113,2131,2137,2179,2237,2239,2293,2297,2311,2371 %N A069791 Primes which yield primes each time the process of removing two outermost digits is carried out until finally a two digit prime (possibly with a leading 0) is obtained. %e A069791 101737 is a member as the number obtained by removing the first and the last digit 0173 is a prime and further removing the first and the last digit gives another prime 17. %t A069791 Select[Prime[Range[PrimePi[1000]+1, PrimePi[9999]]], PrimeQ[FromDigits[Rest[Most[IntegerDigits[#]]]]]&] (* _Harvey P. Dale_, Jan 04 2011 *) %Y A069791 Cf. A069686. %K A069791 base,nonn,changed %O A069791 1,1 %A A069791 _Amarnath Murthy_, Apr 09 2002 %E A069791 Corrected by _T. D. Noe_, Nov 01 2006 %E A069791 Corrected and extended by _Harvey P. Dale_, Jan 04 2011