Irregular triangular array read by rows T(n,k) is the number of 2-colored labeled graphs that have exactly k edges, n >= 2, 0 <= k <= A033638(n).
A201143
Irregular triangular array read by rows T(n,k) is the number of 2-colored labeled graphs that have exactly k edges, n >= 2, 0 <= k <= A033638(n).
Terms
- a(0) =1a(1) =1a(2) =3a(3) =6a(4) =3a(5) =7a(6) =24a(7) =30a(8) =16a(9) =3a(10) =15a(11) =80a(12) =180a(13) =220a(14) =155a(15) =60a(16) =10a(17) =31a(18) =240a(19) =840a(20) =1740a(21) =2340a(22) =2106a(23) =1260a(24) =480a(25) =105a(26) =10a(27) =63a(28) =672a(29) =3360
External references
- oeis: A201143