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 A255480 #12 Mar 10 2015 18:07:08 %S A255480 1,2,3,4,3,2,3,5,2,5,7,3,7,2,3,4,3,4,11,2,11,13,2,13,4,3,2,5,17,5,17, %T A255480 5,3,2,6,19,4,19,2,3,23,3,23,2,3,2,2,4,29,7,29,7,3,7,2,11,31,5,31,5,3, %U A255480 2,2,4,37,4,37,3,3,5,3,4,9,2,6,41,2,41,43,3,43,8,3,4,17 %N A255480 a(n) = gcd(b(n),b(n-2)), where b(n) = A255582(n). %H A255480 Ray Chandler, <a href="/A255480/b255480.txt">Table of n, a(n) for n = 3..10002</a> %o A255480 (Haskell) %o A255480 a255480 n = a255480_list !! (n-1) %o A255480 a255480_list = zipWith gcd a255582_list $ drop 2 a255582_list %o A255480 -- _Reinhard Zumkeller_, Mar 10 2015 %Y A255480 Cf. A255582, A255481, A255102. %Y A255480 Cf. A251102. %K A255480 nonn %O A255480 3,2 %A A255480 _N. J. A. Sloane_, Feb 28 2015