Number of non-monotonic functions from [k] to [n-k].

Terms

a(0) =2a(1) =10a(2) =8a(3) =28a(4) =54a(5) =22a(6) =60a(7) =190a(8) =204a(9) =52a(10) =110a(11) =490a(12) =916a(13) =676a(14) =114a(15) =182a(16) =1050a(17) =2878a(18) =3932a(19) =2118a(20) =240a(21) =280a(22) =1988a(23) =7278a(24) =15210a(25) =16148a(26) =6474a(27) =494a(28) =408a(29) =3444