75369979530domain: NAppears in sequences1/4 the number of (n+1) X 6 binary arrays with equal numbers of 2 X 2 subblocks with sums 1 and 3.at n=5A1846001/4 the number of (n+1) X 7 binary arrays with equal numbers of 2 X 2 subblocks with sums 1 and 3.at n=4A184601