10169108964domain: NAppears in sequencesa(n) = 7*a(n-1) + (-1)^n * binomial(2,2-n) with a(-1)=0.at n=12A055270Triangle read by rows: number of spanning trees obtained for an almost-complete bipartite graph by removing k disjoint edges from the complete bipartite graph K n,n with k<=n.at n=21A260383