Triangular array read by rows. T(n,k) is the number of binary relations on [n] that have exactly k accessible points, n>=0, 0<=k<=n.

A370203

Triangular array read by rows. T(n,k) is the number of binary relations on [n] that have exactly k accessible points, n>=0, 0<=k<=n.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =6a(5) =7a(6) =25a(7) =75a(8) =159a(9) =253a(10) =543a(11) =2172a(12) =6354a(13) =17004a(14) =39463a(15) =29281a(16) =146405a(17) =532130a(18) =1841650a(19) =6808765a(20) =24196201a(21) =3781503a(22) =22689018a(23) =97165485a(24) =395729820a(25) =1801073385a(26) =9917482698a(27) =56481554827

External references