A182728 Array T(n,k) = n*k*A000041(n) read by antidiagonals, n,k >= 1.

1, 4, 2, 9, 8, 3, 20, 18, 12, 4, 35, 40, 27, 16, 5, 66, 70, 60, 36, 20, 6, 105, 132, 105, 80, 45, 24, 7, 176, 210, 198, 140, 100, 54, 28, 8, 270, 352, 315, 264, 175, 120, 63, 32, 9, 420, 540, 528, 420, 330, 210, 140, 72, 36, 10, 616, 840, 810, 704, 525, 396, 245, 160, 81, 40, 11

Offset: 1

Author

Omar E. Pol, Jan 22 2011

Keywords

• nonn
• easy
• tabl

Examples

			Array begins:
    1,   2,   3,   4,   5,   6,   7, ...
    4,   8,  12,  16,  20,  24,  28, ...
    9,  18,  27,  36,  45,  54,  63, ...
   20,  40,  60,  80, 100, 120, 140, ...
   35,  70, 105, 140, 175, 210, 245, ...
   66, 132, 198, 264, 330, 396, 462, ...
  105, 210, 315, 420, 525, 630, 735, ...
		

Crossrefs

Cf. A000041, A135010, A182729, A183011.

Column 1 gives A066186. Column 24 gives A183009.

Programs

Maple

A182728 := proc(n,k) n*k*combinat[numbpart](n) ; end proc:
seq(seq( A182728(d+1-k, k), k=1..d), d=1..10) ; # R. J. Mathar, Feb 01 2011