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 A151910 #9 Jul 13 2013 12:03:35 %S A151910 21,21,23,21,23,21,21,23,21,23,21,23,21,21,23,21,23,21,23,21,21,23,21, %T A151910 23,21,23,21,21,23,21,23,21,23,21,21,23,21,23,21,23,21,21,23,21,23,21, %U A151910 23,21,21,23,21,23,21,23,21,21,23 %N A151910 First differences of A001682. %C A151910 a(n) = A001682(n+1) - A001682(n). %H A151910 Reinhard Zumkeller, <a href="/A151910/b151910.txt">Table of n, a(n) for n = 1..1000</a> %o A151910 (Haskell) %o A151910 a151910 n = a151910_list !! (n-1) %o A151910 a151910_list = zipWith (-) (tail a001682_list) a001682_list %o A151910 -- _Reinhard Zumkeller_, Oct 10 2011 %K A151910 nonn %O A151910 1,1 %A A151910 _Harvey P. Dale_, Aug 08 2009 %E A151910 Offset corrected and initial term added by _Reinhard Zumkeller_, Oct 10 2011