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 A252802 #23 Jul 01 2021 15:45:53
%S A252802 3,11,19
%N A252802 Primes whose trajectory under the map x -> A039951(x) enters the cycle {3, 11, 71}.
%C A252802 From _Felix Fröhlich_, Jul 01 2021: (Start)
%C A252802 Further terms in the sequence are 71, 107, 127, 139, 167, 179, etc. The smallest prime where it is unknown whether it is in this sequence (or in A252801 or A252812) is 47.
%C A252802 Is A000040 the union of this sequence, A252801 and A252812? (End)
%e A252802 The trajectory of 19 under the given map starts 19, 3, 11, 71, 3, ..., entering the given cycle, so 19 is a term of the sequence.
%Y A252802 Cf. A000040, A039951, A244550, A252801, A252812.
%K A252802 nonn,hard,more,bref
%O A252802 1,1
%A A252802 _Felix Fröhlich_, Dec 22 2014
%E A252802 Name edited by _Felix Fröhlich_, Jun 19 2021