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 A110977 #9 Sep 04 2014 08:01:38 %S A110977 1,1,1,1,2,1,3,1,4,9,13,9,22,9,31,71,102,71,173,71,244,559,803,559, %T A110977 1362,3283,11211,25705,36916,25705,62621,25705,88326,202357,695397, %U A110977 1593151,2288548,1593151,3881699,9356549,13238248,9356549,22594797,9356549 %N A110977 Sequence of denominators associated with the continued fraction based on the sequence d(n)= distance of n from closest prime ( A051699). %D A110977 G. Balzarotti and P. P. Lava, Le sequenze di numeri interi, Hoepli, 2008, p. 110. %F A110977 See program. %e A110977 if n = 2, B(n) = B(2) = 1 because B(0) = 1, B(1) = 1 * B(0) = 1 as the distances of n from closest prime are 2, 1, 0, 0, 1 ... %p A110977 A[0]:=d[0]; A[1]:=d[1]*A[0]+1; B[0]:=1; B[1]:=d[1]*B[0]; for n from 2 by 1 to N do A[n]:=d[n]*A[n-1]+A[n-2]; B[n]:=d[n]*B[n-1]+B[n-2]; od; %Y A110977 Cf. A051699, A109139, A109140, A110976. %K A110977 frac,nonn %O A110977 0,5 %A A110977 _Giorgio Balzarotti_ and _Paolo P. Lava_, Sep 28 2005