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 A219843 #17 Aug 29 2023 03:47:26 %S A219843 0,0,2,0,14,12,42,0,254,252,762,240,3822,3276,10922,0,65534,65532, %T A219843 196602,65520,983022,851916,2817962,65280,16711422,16579836,50002682, %U A219843 15790320,250539758,214748364,715827882,0,4294967294,4294967292,12884901882,4294967280 %N A219843 Rows of A219463 seen as numbers in binary representation. %H A219843 Reinhard Zumkeller, <a href="/A219843/b219843.txt">Table of n, a(n) for n = 0..1000</a> %F A219843 a(n) = A000225(n+1) - A001317(n); %F A219843 A000120(a(n)) = A048967(n); %F A219843 a(A000225(n)) = 0. %t A219843 A219843[n_]:=FromDigits[Sign[BitAnd[Range[n],-1-n]],2];Array[A219843,50,0] (* _Paolo Xausa_, Aug 29 2023 *) %o A219843 (Haskell) %o A219843 a219843 = foldr (\u v-> 2*v + u) 0 . map toInteger . a219463_row %o A219843 (Python) %o A219843 def A219843(n): return (1<<n+1)-1-sum((bool(~n&n-k)^1)<<k for k in range(n+1)) # _Chai Wah Wu_, May 03 2023 %K A219843 nonn,base %O A219843 0,3 %A A219843 _Reinhard Zumkeller_, Nov 30 2012