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 A340618 #23 Feb 06 2021 22:09:16 %S A340618 13,15,19,23,31,33,35,37,43,47,51,52,59,73,78,85,93,94,97,99,105,106, %T A340618 109,113,115,119,127,129,139,141,149,159,163,165,168,169,179,181,189, %U A340618 199,211,213,218,231,232,237,245,251,256,258,259,271,273,274,275,294,301,303,304,307,339,344,347,348 %N A340618 Numbers k such that A316650(k) is prime. %H A340618 Robert Israel, <a href="/A340618/b340618.txt">Table of n, a(n) for n = 1..10000</a> %e A340618 a(4) = 23 is a term because A316650(23) = 43 is prime. %p A340618 f:= proc(n) local a,b,c; %p A340618 c:= convert(convert(n,base,10),`+`); %p A340618 a:= floor(n/c); %p A340618 b:= n mod c; %p A340618 10^(1+ilog10(b))*a+b; %p A340618 end proc: %p A340618 select(n -> isprime(f(n)), [$1..100]); %Y A340618 Cf. A316650. %K A340618 nonn,base %O A340618 1,1 %A A340618 _J. M. Bergot_ and _Robert Israel_, Jan 15 2021