Number of essentially parallel oriented series-parallel networks with n elements and without multiple unit elements in parallel.

A339289

Number of essentially parallel oriented series-parallel networks with n elements and without multiple unit elements in parallel.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =2a(4) =5a(5) =14a(6) =39a(7) =117a(8) =353a(9) =1099a(10) =3458a(11) =11066a(12) =35738a(13) =116622a(14) =383448a(15) =1269869a(16) =4230557a(17) =14170956a(18) =47693457a(19) =161207066a(20) =546987882a(21) =1862464911a(22) =6361729689a(23) =21793247587a(24) =74855427331a(25) =257743707769a(26) =889477338903

External references