Number of 2-line arrays; or number of P-graphs with 2n edges.
A003169
Number of 2-line arrays; or number of P-graphs with 2n edges.
Terms
- a(0) =1a(1) =3a(2) =14a(3) =79a(4) =494a(5) =3294a(6) =22952a(7) =165127a(8) =1217270a(9) =9146746a(10) =69799476a(11) =539464358a(12) =4214095612a(13) =33218794236a(14) =263908187100
External references
- oeis: A003169