Number of subgraphs of the directed square lattice with n edges and all vertices reachable from the origin.

A344571

Number of subgraphs of the directed square lattice with n edges and all vertices reachable from the origin.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =14a(4) =42a(5) =130a(6) =412a(7) =1326a(8) =4318a(9) =14188a(10) =46950a(11) =156258a(12) =522523a(13) =1754254a(14) =5909419a(15) =19964450a(16) =67618388a(17) =229526054a(18) =780633253a(19) =2659600616a(20) =9075301990a(21) =31010850632a(22) =106100239080a(23) =363428599306

External references