Rectangular array A read by upward antidiagonals: A(n,m) is the number of surjective difunctional (regular) binary relations between an n-element set and an m-element set.
A265707
Rectangular array A read by upward antidiagonals: A(n,m) is the number of surjective difunctional (regular) binary relations between an n-element set and an m-element set.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =1a(4) =5a(5) =7a(6) =1a(7) =9a(8) =19a(9) =15a(10) =1a(11) =17a(12) =49a(13) =65a(14) =31a(15) =1a(16) =33a(17) =127a(18) =225a(19) =211a(20) =63a(21) =1a(22) =65a(23) =337a(24) =749a(25) =961a(26) =665a(27) =127a(28) =1a(29) =129
External references
- oeis: A265707