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 A263413 #24 Dec 08 2015 01:49:11 %S A263413 0,1,2,5,151,661,521,49993,858868651,115523,72920757563,3844109, %T A263413 1637177,7158605959,17024617,13062611,66113257898351335849, %U A263413 599880481206897379,745125370039,4314028165895642655831229,30699710580827,1744795596758086587163381,2463356705098399667815003 %N A263413 Largest prime (or noncomposite) factor of the Crandall number A262961(n). %C A263413 Computed up to n = 94 by _David Broadhurst_, and independently up to n = 67 by _Hans Havermann_ and _M. F. Hasler_. %C A263413 At n = 95 and n = 96 we have composite factors of 157 digits with probably no divisor less than 50 digits. - _David Broadhurst_, Oct 17 2015 %H A263413 David Broadhurst, <a href="/A263413/b263413.txt">Table of n, a(n) for n = 1..94</a> %H A263413 Hans Havermann and David Broadhurst, <a href="http://chesswanks.com/num/CrandallNumbersFactored.txt">Crandall Numbers Factored</a> %F A263413 a(n) = A006530(A262961(n)). %o A263413 (PARI) a(n)=A006530(A262961(n)) \\ _M. F. Hasler_, Oct 17 2015 %Y A263413 Cf. A262961. %K A263413 nonn,hard %O A263413 1,3 %A A263413 _M. F. Hasler_, Oct 17 2015