A triangular sequence based on a two sequence lower triangular matrix. a(n)=(-1)^n*(n-1)!; b[n]=(n-1)!; M(i,j)={{a(i),b(j)},{b(j),a(i+1)}}; a0(i,j)=Det[M(i,j)]; This method gives an tridiagonal matrix effect to a lower triangular matrix base.
1, 1, 2, 2, 5, 3, 18, 39, 23, 4, 1152, 2064, 872, 119, 5, 720000, 1122000
1 seqfan posts
Wed Aug 18 20:41:17 CEST 2010 [seqfan] Re: A135282: We can go ahead and change "seems" to "is known"