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 A107122 #19 Jul 31 2025 22:03:12
%S A107122 31,161159,2935241,12393851,25792148743,8378273888129
%N A107122 Numbers m such that m=prime(prime(prime(d_1*d_2*...*d_k))) where d_1 d_2 ... d_k is the decimal expansion of m.
%C A107122 a(7) > 7*10^14, if it exists. - _Giovanni Resta_, Jun 01 2020
%C A107122 The sequence is finite as m > 10^(k-1) grows faster than prime(prime(prime(9^k))) >= prime(prime(prime(d_1*d_2*...*d_k))). - _Max Alekseyev_, Dec 30 2024
%e A107122 12393851 is in the sequence because 12393851 = prime(prime(prime(1*2*3*9*3*8*5*1))).
%t A107122 Do[h= IntegerDigits[Prime[m]];l = Length[h];If[Min[h] > 0 && m == Prime[Prime[Prime[Product[h[[k]], {k, l}]]], Print[Prime[m]]]], {m, 10000000}]
%Y A107122 Cf. A097223, A107120, A107121.
%K A107122 nonn,base,fini,more
%O A107122 1,1
%A A107122 _Farideh Firoozbakht_, May 13 2005, May 27 2008
%E A107122 a(6) from _Giovanni Resta_, Jun 01 2020