A198889 Square array in A071223 read by antidiagonals.

2, 2, 2, 2, 6, 2, 2, 12, 6, 2, 2, 20, 24, 6, 2, 2, 30, 72, 24, 6, 2, 2, 42, 172, 120, 24, 6, 2, 2, 56, 352, 480, 120, 24, 6, 2, 2, 72, 646, 1512, 720, 120, 24, 6, 2, 2, 90, 1094, 3976, 3600, 720, 120, 24, 6, 2, 2, 110, 1742, 9144, 14184, 5040, 720, 120, 24, 6, 2, 2, 132, 2642, 18990, 45992, 30240, 5040, 720, 120

Offset

2,1

Links

Table of n, a(n) for n=2..76.

T. M. Cover, The number of linearly inducible orderings of points in d-space, SIAM J. Applied Math., 15 (1967), 434-439.

Formula

See A071223, which is the main entry for this array.

Example

Array begins
  2  2   2   2   2  ...
  2  6   6   6   6 ...
  2 12  24  24  24 ...
  2 20  72 120 120 ...
  2 30 172 480 720 ...
  ...

Maple

A071223 := proc(n, k)
        if k=1 and n>=2 then
                2
        elif n=2 and k>=1 then
                2
        elif k>=n-1 then
                n!
        else
        procname(n-1, k)+(n-1)*procname(n-1, k-1)
        fi ;
end proc:
for d from 3 to 16 do
        for k from 1 to d-2 do
                n := d-k ;
                printf("%d, ", A071223(n, k)) ;
        end do:
end do; # R. J. Mathar, Oct 31 2011

Crossrefs

Cf. A071223.

Sequence in context: A278260 A070877 A156717 * A329814 A130754 A164126

Adjacent sequences: A198886 A198887 A198888 * A198890 A198891 A198892

Keyword

nonn,tabl

Author

N. J. A. Sloane, Oct 30 2011

Status

approved