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 A089939 #14 Aug 23 2022 09:49:27 %S A089939 1,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,0,1,1,0,1,1,1,1,0,1,1,1,1,0,1,0,0,1, %T A089939 0,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,0,1,1,1,0,1,1,0,0,0,1,1,0,1,1,1, %U A089939 1,1,1,0,0,1,1,1,1,1,1,1,0,1,1,0,0,0,1,1,0,1,1,1,0,1,1,0,1,0,0,1,0,1,1,0,1 %N A089939 T(i,j) = 1 if F(i) AND F(j) = 0, otherwise 0, where F is A003714 and AND is the bitwise logical-and operation. Table read by antidiagonals. %C A089939 Encodes which row/column patterns may be adjacent in 01-matrices where no two 0 elements may be adjacent. Contains many interesting recursive patterns such as Fibonacci-sized blocks of 0's along main diagonal. %e A089939 T(3,4) = 0 because F(3) AND F(4) = 4 AND 5 = 1, which is nonzero. %Y A089939 Cf. A003714 (Fibbinary), A005614 (row or column 1). %Y A089939 Cf. A000045, A047999. %Y A089939 Cf. A001333, A051736, A051737, A089934, A089935, A089936, A089937, A089938. %K A089939 base,easy,nonn,tabl %O A089939 0,1 %A A089939 _Marc LeBrun_, Nov 15 2003 %E A089939 Name clarified by _Jon E. Schoenfield_, Aug 19 2022