131862domain: NAppears in sequences1/4 the number of (n+1) X 6 binary arrays with all 2 X 2 subblock sums the same.at n=17A183982Matula-Goebel numbers of unlabeled rooted identity RPMG-trees, meaning the Matula-Goebel numbers of the branches of any non-leaf node are relatively prime.at n=27A316469