Table, T(n,k) is the number of categories with n morphisms and k objects.

Terms

a(0) =1a(1) =2a(2) =1a(3) =7a(4) =3a(5) =1a(6) =35a(7) =16a(8) =3a(9) =1a(10) =228a(11) =77a(12) =20a(13) =3a(14) =1a(15) =2237a(16) =485a(17) =111a(18) =21a(19) =3a(20) =1a(21) =31559a(22) =4013a(23) =716a(24) =127a(25) =21a(26) =3a(27) =1a(28) =1668997a(29) =47648