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 A347679 #21 Sep 11 2021 19:23:08 %S A347679 0,1,0,0,2,4,0,0,0,3,24,26,0,0,0,0,8,98,284,214,0,0,0,0,0,19,374,1922, %T A347679 3496,2030,0,0,0,0,0,0,44,1342,10620,33398,44674,21174,0,0,0,0,0,0,0, %U A347679 111,4596,51904,245684,554500,589092,236410 %N A347679 Irregular triangle read by rows: T(n,k) (1 <= k <= 2*n) = number of n X k Baxter matrices in which all row sums are 2. %H A347679 Don Knuth, <a href="https://cs.stanford.edu/~knuth/papers/baxter-matrices.pdf">Baxter matrices</a>, Preprint, Sep 05 2021. %e A347679 The T(4,5)=8 matrices of size 4 X 5 are %e A347679 . %e A347679 0 0 0 1 1 0 0 0 1 1 0 1 0 0 1 1 0 0 0 1 %e A347679 0 0 1 1 0 1 0 0 1 0 0 0 1 1 0 0 0 1 1 0 %e A347679 0 1 1 0 0 0 1 1 0 0 0 1 0 0 1 0 1 1 0 0 %e A347679 1 1 0 0 0 1 0 0 1 0 1 1 0 0 0 1 0 0 0 1 %e A347679 . %e A347679 1 0 0 0 1 1 0 0 1 0 1 1 0 0 0 1 1 0 0 0 %e A347679 0 1 1 0 0 0 1 1 0 0 0 1 0 0 1 0 1 1 0 0 %e A347679 0 0 1 1 0 1 0 0 1 0 0 0 1 1 0 0 0 1 1 0 %e A347679 1 0 0 0 1 0 0 0 1 1 0 1 0 0 1 0 0 0 1 1 %Y A347679 Cf. A347678, A347736 (superdiagonal). %K A347679 nonn,tabf,more %O A347679 1,5 %A A347679 _N. J. A. Sloane_, Sep 10 2021