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 A377068 #7 Oct 15 2024 15:46:50
%S A377068 1,1,10,30,117,345,1042,2746,7063,16759,38440,83476,175473,354105,
%T A377068 694278,1318222,2440888,4402852,7770908,13418156,22734824,37807500,
%U A377068 61839510,99526422,157858478,246864782,381087734,580990046,875572808,1304930876,1924761300,2810843268
%N A377068 Number of n X 4 0..2 matrices with row sums 4 and column sums n up to permutations of rows.
%C A377068 Also, the number of n X 4 {-1,0,1} matrices with all rows and columns summing to zero up to permutations of rows.
%e A377068 The a(2) = 10 matrices are:
%e A377068 [1 1 2 0] [1 2 1 0] [1 2 0 1] [2 1 1 0] [2 1 0 1] [2 0 1 1]
%e A377068 [1 1 0 2] [1 0 1 2] [1 0 2 1] [0 1 1 2] [0 1 2 1] [0 2 1 1]
%e A377068 .
%e A377068 [1 1 1 1] [2 2 0 0] [2 0 2 0] [2 0 0 2]
%e A377068 [1 1 1 1] [0 0 2 2] [0 2 0 2] [0 2 2 0]
%Y A377068 Column k=4 of A377063.
%Y A377068 Cf. A172642, A377066, A377067.
%K A377068 nonn
%O A377068 0,3
%A A377068 _Andrew Howroyd_, Oct 15 2024