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 A141396 Triangle read by rows, antidiagonals of a multiplication table: 3^n * (numbers not multiples of 3). 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 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Ternary representation of terms in n-th row have n rightmost adjacent zeros. Row sums = A141397: (1, 5, 19 62, 193, 587, ...). LINKS Ivan Neretin, Table of n, a(n) for n = 0..5049 FORMULA Triangle read by rows, descending antidiagonals of the multiplication table: (top row, numbers not multiples of 3); leftmost column, 3^n. EXAMPLE 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;   ... MATHEMATICA Flatten[Table[3^k*Quotient[(3 (m - k) - 1), 2], {m, 0, 10}, {k, 0, m - 1}]] (* Ivan Neretin, Nov 26 2016 *) CROSSREFS Cf. A001651, A141397. Sequence in context: A233559 A285332 A185290 * A159849 A098168 A306441 Adjacent sequences:  A141393 A141394 A141395 * A141397 A141398 A141399 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Jun 29 2008 STATUS approved

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Last modified August 11 19:16 EDT 2020. Contains 336428 sequences. (Running on oeis4.)