128146domain: NAppears in sequencesa(n) = Sum_{k >= 1} floor(2*tau^(n-k)).at n=21A020957G.f.: 1/(1-x)^3 * Product_{k>=1} (1 + x^k).at n=33A325951Number of regions formed when every pair of vertices of a regular n-gon are joined by an infinite line.at n=33A345025