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 A095386 #6 Sep 04 2017 19:26:58 %S A095386 2,2,2,2,2,13,2,13,2,13,2,5,13,5,2,13,13,11,5,2,13,5,3,11,5,577,13,11, %T A095386 5,577,2,5,13,5,13,7,11,19,5,577,2,7,13,17,5,577,3,37,11,29,13,5,577, %U A095386 577,7,7,11,19,5,23,577,577,2,7,5,19,17,13,5,577,3,577,7,17,11,29,19,101,5 %N A095386 Largest prime factor of peak values of 3x+1 trajectory started at n. %F A095386 a(n) = A006530(A025586(n)). %e A095386 n=27: peak = 9232 = 2*2*2*2*577, so a(27)=577; %e A095386 more extensive search suggests that all primes may occur as largest prime factor of peak. %Y A095386 Cf. A006530, A025586. %K A095386 nonn %O A095386 2,1 %A A095386 _Labos Elemer_, Jun 14 2004