Number of minimum vertex colorings in the complement of the path graph on n nodes.

Terms

a(0) =1a(1) =1a(2) =4a(3) =2a(4) =18a(5) =6a(6) =96a(7) =24a(8) =600a(9) =120a(10) =4320a(11) =720a(12) =35280a(13) =5040a(14) =322560a(15) =40320a(16) =3265920a(17) =362880a(18) =36288000a(19) =3628800a(20) =439084800a(21) =39916800a(22) =5748019200a(23) =479001600a(24) =80951270400a(25) =6227020800a(27) =87178291200