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 A382198 #11 Mar 18 2025 16:23:14 %S A382198 3,14,153,2169,48165,125769,327174495 %N A382198 Smallest integer k with n distinct digits, such that for each digit of k, 2*k*(digit) + 1 is prime. %C A382198 See 1st comment of A382127 for an explanation that there cannot be more than 7 terms. %o A382198 (PARI) isok(k, n) = my(d=Set(digits(k))); if (#d != n, return(0)); for (i=1, #d, if (!isprime(2*k*d[i]+1), return(0)); ); return(1); %o A382198 a(n) = my(k=2); while (!isok(k, n), k++); k; %Y A382198 Subsequence of A382179. %Y A382198 Cf. A382127, A382199. %K A382198 nonn,base,fini,full %O A382198 1,1 %A A382198 _Michel Marcus_, Mar 18 2025