A141396 Triangle read by rows, antidiagonals of a multiplication table: 3^n * (numbers not multiples of 3).

1, 2, 3, 4, 6, 9, 5, 12, 18, 27, 7, 15, 36, 54, 81, 8, 21, 45, 108, 162, 243, 10, 24, 63, 135, 324, 486, 729, 11, 30, 72, 189, 405, 972, 1458, 2187, 13, 33, 90, 216, 567, 1215, 2916, 4374, 6561, 14, 39, 99, 270, 648, 1701, 3645, 8748, 13122, 19683, 16, 42, 117, 297

Offset: 0

Author

Gary W. Adamson, Jun 29 2008

Keywords

• nonn
• tabl

Comments

Ternary representation of terms in n-th row have n rightmost adjacent zeros.

Row sums = A141397: (1, 5, 19 62, 193, 587, ...).

Examples

			The array begins:
   1,   2,   4,   5,   7, ...
   3,   6,  12,  15,  21, ...
   9,  18,  36,  45,  63, ...
  27,  54, 108, 135, 189, ...
  81, 162, 324, 405, 567, ...
  ...
Descending antidiagonals of the array give
   1;
   2,    3;
   4,    6,    9;
   5,   12,   18,   27;
   7,   15,   36,   54,   81;
   8,   21,   45,  108,  162,  243;
  10,   24,   63,  135,  324,  486,  729;
  11,   30,   72,  189,  405,  972, 1458, 2187;
  ...
		

Links

• Ivan Neretin, Table of n, a(n) for n = 0..5049

Crossrefs

Cf. A001651, A141397.

Programs

Mathematica

Flatten[Table[3^k*Quotient[(3 (m - k) - 1), 2], {m, 0, 10}, {k, 0, m - 1}]] (* Ivan Neretin, Nov 26 2016 *)

Formula

Triangle read by rows, descending antidiagonals of the multiplication table: (top row, numbers not multiples of 3); leftmost column, 3^n.