7855628

Appears in sequences

• Number of 4-chromatic (i.e., chromatic number equals 4) simple graphs on n nodes.at n=9A076280
• Triangle read by rows: T(n,k) is the number of simple graphs on n unlabeled nodes having chromatic number k, 1 <= k <= n.at n=48A084268
• Triangle read by rows: let a(n,k) = number of graphs on n nodes with chromatic number k; T(n,k) = a(n,n-k), n >= 2, k=0..n-2.at n=42A115597