429030domain: NAppears in sequencesNumber of 4-indecomposable (connected) graphs on n nodes.at n=33A128526Antidiagonal sums of the convolution array A213822.at n=26A213824Triangle read by rows: T(n,k) is the coefficient of x^k in the ZZ polynomial of the hexagonal graphene flake O(3,3,n).at n=39A338158