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 A030339 #11 Jun 19 2025 21:27:42 %S A030339 1,1,2,1,2,3,4,4,4,3,3,4,4,4,5,4,3,4,3,4,5,4,4,5,6,5,6,7,8,9,10,10,11, %T A030339 11,10,11,11,12,13,13,13,13,12,11,11,10,11,11,10,10,10,11,10,10,11,12, %U A030339 12,13,13,13,13,12,12,12,13,13,13,13,14,13 %N A030339 (# 1's)-(# 0's) in first n terms of A003137. %H A030339 Reinhard Zumkeller, <a href="/A030339/b030339.txt">Table of n, a(n) for n = 1..10000</a> %o A030339 (Haskell) %o A030339 a030339 n = a030339_list !! (n-1) %o A030339 a030339_list = scanl1 %o A030339 (\u v -> u + fromEnum (v == 1) - fromEnum (v == 0)) a003137_list %o A030339 -- _Reinhard Zumkeller_, Feb 21 2013 %Y A030339 Cf. A003137, A030340. %K A030339 nonn %O A030339 1,3 %A A030339 _Clark Kimberling_