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 A342961 #17 Apr 01 2021 05:08:26 %S A342961 11,19,29,37,41,53,61,73,89,101,109,149,181,191,199,229,233,257,269, %T A342961 277,281,307,331,359,379,383,401,409,419,433,449,461,491,499,563,587, %U A342961 593,601,619,641,653,661,673,677,691,727,797,809,811,821,881,911,919,937,941,977,991,1009,1019,1033 %N A342961 Primes p such that p + the sum of its prime digits is prime. %H A342961 Robert Israel, <a href="/A342961/b342961.txt">Table of n, a(n) for n = 1..10000</a> %e A342961 a(3) = 29 is a term because it is prime, the sum of its prime digits is 2, and 29+2 = 31 is also prime. %p A342961 f:= p -> p + convert(select(isprime,convert(p,base,10)),`+`): %p A342961 select(t -> isprime(t) and isprime(f(t)), [seq(i,i=3..2000,2)]); %t A342961 Select[Prime@Range@200,PrimeQ@Total[Join[{#},Select[IntegerDigits@#,PrimeQ]]]&] (* _Giorgos Kalogeropoulos_, Apr 01 2021 *) %o A342961 (PARI) isok(p) = isprime(p) && isprime(p+sumdigits(p)); \\ _Michel Marcus_, Apr 01 2021 %Y A342961 Includes A034844. Cf. A085563, A342962. %K A342961 nonn,base %O A342961 1,1 %A A342961 _J. M. Bergot_ and _Robert Israel_, Mar 31 2021