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 A086402 #8 Jun 08 2025 16:15:42
%S A086402 13,17,37,79,113,131,149,157,163,167,179,181,191,197,199,241,251,281,
%T A086402 313,337,347,359,373,389,419,461,463,491,563,571,593,613,617,683,719,
%U A086402 787,797,839,919,1163,1181,1193,1217,1223,1229,1237,1249,1259,1279,1297
%N A086402 Nontrivial numbers which are prime and yield another prime when their digits are sorted in descending order.
%C A086402 Primes with digits already in descending order (like 311 and 3221) are trivial cases and are therefore excluded.
%e A086402 a(1)=13 because a descending sort of 13's digits yields 31 which is also prime. a(100)=2411 because a descending sort of 2411's digits yields 4211 which is also prime.
%t A086402 pdsdQ[p_]:=With[{d=FromDigits[ReverseSort[IntegerDigits[p]]]},d!=p&&PrimeQ[d]]; Select[Prime[Range[250]],pdsdQ] (* _Harvey P. Dale_, Oct 03 2024 *)
%Y A086402 Cf. A003459.
%K A086402 base,nonn
%O A086402 1,1
%A A086402 _Chuck Seggelin_, Jul 07 2003