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 A238850 #19 Nov 07 2024 21:59:38 %S A238850 2,3,5,7,31,37,71,73,79,311,313,373,733,739,797,3733 %N A238850 Right-truncatable reversible primes in base 10. %C A238850 In a general base b, a number qualifies as a member iff: (i) it is a prime, (ii) when its digits in base b are reversed, it is still a prime, and (iii) when, in base b, it has more than one digit and the least significant one is dropped, the remaining prefix has the same properties. This implies that any base-b prefix of such a number, no matter how many right-side digits are truncated, is still a right-truncatable reversible prime. Sequences of this type appear to be all finite (see A238854, A238855, and A238856, used as examples). %C A238850 This particular sequence is for base b = 10. %C A238850 See also A238854 for comments on a more general context. %H A238850 Stanislav Sykora, <a href="https://oeis.org/wiki/File:GeneticThreads.txt">PARI/GP scripts for genetic threads</a>, with code and comments. %e A238850 739 is a member because it is a prime and so is 937, as well as the pair (73, 37) and 7. %o A238850 (PARI) See the link. %Y A238850 In base 16: A238851, 100: A238852, 256: A238853. %Y A238850 In base n: A238854 (largest), A238855 (totals), A238856 (maximum digits), A238857 (m-digit counts). %Y A238850 Cf. A007500, A023107, A024770, A237600, A237601, A237602. %K A238850 nonn,fini,full,base,easy %O A238850 1,1 %A A238850 _Stanislav Sykora_, Mar 06 2014