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 A055019 #27 Dec 15 2017 17:34:52 %S A055019 1,2,3,4,5,7,8,9,10,11,13,14,20,22,25,40,41,55,57,64,77,125,663,1053, %T A055019 1414,1711,2822,2956,4107,7463 %N A055019 Numbers n such that A051885(p_n) is prime, where p_n=A000040(n) is the n-th prime. %C A055019 Numbers n such that A051885(A000040(n)) = A054750(n). %C A055019 No other terms below 10^4. %e A055019 The 125th prime is 691. The least integer with sum of digits 691 is A051885(691) = 8*10^76-1 which is prime. This is the 22nd prime with this property, so a(22)=125. %o A055019 (PARI) for(X=1,300, a=prime(X)%9; b=prime(X)\9; m=(a+1)*10^b-1; if(isprime(m), print([X,prime(X),m]) ) ) %Y A055019 Cf. A054750, A051885. %K A055019 more,nonn,base %O A055019 1,2 %A A055019 Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), May 31 2000 %E A055019 More terms from _Jason Earls_, Jun 22 2001 %E A055019 a(27)-a(30) from _Max Alekseyev_, Dec 09 2011