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 A343128 #17 Apr 14 2021 22:42:31 %S A343128 7,229,417,657,26203,32553,50971,93487,231221,17064941,54784601, %T A343128 93007099,981668491,16040988367 %N A343128 Numbers k such that prime(prime(prime(k))) ends in k. %e A343128 417 is a term since prime(prime(prime(417))) = 302417. %e A343128 26203 is a term since prime(prime(prime(26203))) = 73226203. %e A343128 17064941 is a term since prime(prime(prime(17064941))) = 169217064941. %e A343128 prime(prime(prime(54784601))) = 647454784601, prime(prime(prime(93007099))) = 1185993007099, prime(prime(prime(981668491))) = 17148981668491, prime(prime(prime(16040988367))) = 390416040988367. - _Chai Wah Wu_, Apr 14 2021 %o A343128 (Python) %o A343128 A343128_list = [n for n in range(1,10**4) if n % 2 and n % 5 and prime(prime(prime(n))) % 10**(len(str(n))) == n] %Y A343128 Cf. A046883, A074978. %K A343128 nonn,base,more %O A343128 1,1 %A A343128 _Chai Wah Wu_, Apr 06 2021 %E A343128 a(11)-a(14) from _Chai Wah Wu_, Apr 14 2021