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 A353963 #34 Mar 31 2025 22:59:28
%S A353963 1,1,1,1,1,6,1,1,13,47,1,1,45,259,3376,1,1,122,1189,29683,475962,1,1,
%T A353963 373,5877,311894,9250945,355724934,1,1,1073,28167,3015423,164776003,
%U A353963 12126673297,777719132265,1,1,3182,136723,30295051,3051272172,436744432876,53090133270415,6953251175836902
%N A353963 Triangle read by rows: T(n,k) = number of tilings of a n X k rectangle using 2 X 2 and 1 X 1 tiles and right trominoes, n >= 0, k=0..n.
%C A353963 For tiling algorithm, see A351322.
%C A353963 Reading the sequence {T(n,k)} for k>n, use T(k,n) instead of T(n,k).
%H A353963 Liang Kai, <a href="/A353963/b353963.txt">Rows n=0..17 of triangle, flattened</a>
%e A353963 Triangle begins
%e A353963 n\k 0 1 2 3 4 5 6
%e A353963 ------------------------------------------
%e A353963 0: 1
%e A353963 1: 1 1
%e A353963 2: 1 1 6
%e A353963 3: 1 1 13 47
%e A353963 4: 1 1 45 259 3376
%e A353963 5: 1 1 122 1189 29683 475962
%e A353963 6: 1 1 373 5877 311894 9250945 355724934
%o A353963 (Maxima) See A352589.
%Y A353963 Row/columns 0..3 are A000012, A000012, A353964, A353965.
%Y A353963 Main diagonal is A354067.
%Y A353963 Cf. A351322, A352589.
%K A353963 nonn,tabl
%O A353963 0,6
%A A353963 _Gerhard Kirchner_, May 13 2022