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 A198146 #17 Oct 30 2018 10:31:02
%S A198146 2293,2393,2591,2693,2791,2903,2957,5297,5927,7297,7927,8293,8923,
%T A198146 9203,9257,9323,9521,9623,9721,9923,12491,12497,12907,12911,12967,
%U A198146 12973,13291,13921,14293,14923,17291,17293,17921,17923,19207,19211,19267,19273,19421,19427
%N A198146 Primes remaining primes under map 2<=>9 (interchange of decimal digits 2 and 9).
%C A198146 Only primes containing at least one "2" and one "9" are considered.
%C A198146 Inspired by history (told by VIA himself) that most often mistakes made by V. I. Arnold were caused by mixing 2's and 9's (and also 3's and 5's) in the lengthy calculations by hand.
%H A198146 V. I. Arnold, <a href="http://www.mccme.ru/free-books/dubna/via-exp.pdf">Experimental observation of mathematical facts (in Russian)</a>
%e A198146 2293, 9923 both primes; 2393, 9323 both primes.
%t A198146 p = 29; Reap[Do[id = IntegerDigits[p]; If[Count[id, 2] > 0 && Count[id, 9] > 0 && PrimeQ[FromDigits[(id /. {2 -> a, 9 -> 2}) /. {a -> 9}]], Sow[p]]; p = NextPrime[p], {10^4}]][[2,1]]
%Y A198146 Cf. A198047 (map 3 <=> 5).
%K A198146 nonn,base
%O A198146 1,1
%A A198146 _Zak Seidov_, Oct 21 2011