T(n,k) is the number of partial bijections (or subpermutations) of an n-element set of height k (height(alpha) = |Im(alpha)|) and with exactly 2 fixed points.

A144091

T(n,k) is the number of partial bijections (or subpermutations) of an n-element set of height k (height(alpha) = |Im(alpha)|) and with exactly 2 fixed points.

Terms

    a(0) =1a(1) =3a(2) =0a(3) =6a(4) =12a(5) =6a(6) =10a(7) =60a(8) =90a(9) =20a(10) =15a(11) =180a(12) =630a(13) =660a(14) =135a(15) =21a(16) =420a(17) =2730a(18) =6720a(19) =5565a(20) =924a(21) =28a(22) =840a(23) =8820a(24) =39760a(25) =76020a(26) =51912a(27) =7420a(28) =36a(29) =1512

External references