Triangle of numbers of squares {i^2}, i = 0,1..ceiling(n/2), in permutations of {1..n} in A293857.

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =2a(5) =0a(6) =2a(7) =8a(8) =0a(9) =4a(10) =0a(11) =24a(12) =0a(13) =12a(14) =0a(15) =108a(16) =0a(17) =36a(18) =576a(19) =0a(20) =720a(21) =0a(22) =144a(23) =4608a(24) =0a(25) =4032a(26) =0a(27) =576a(28) =0a(29) =31680