Triangle read by rows: T(n,k) is the number of binary relations on a set of n objects, exactly k of which are self referencing, 0 <= k <= n.

A384105

Triangle read by rows: T(n,k) is the number of binary relations on a set of n objects, exactly k of which are self referencing, 0 <= k <= n.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =4a(5) =3a(6) =16a(7) =36a(8) =36a(9) =16a(10) =218a(11) =752a(12) =1104a(13) =752a(14) =218a(15) =9608a(16) =45960a(17) =90416a(18) =90416a(19) =45960a(20) =9608a(21) =1540944a(22) =9133760a(23) =22692704a(24) =30194176a(25) =22692704a(26) =9133760a(27) =1540944a(28) =882033440a(29) =6154473664

External references