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A128089
Denominators in inverse of triangle A128078 by rows, n * each term in n-th row of A126615.
0
1, 4, 4, 6, 18, 9, 8, 24, 48, 16, 10, 30, 60, 100, 25, 12, 36, 72, 120, 180, 36, 14, 42, 84, 140, 210, 294, 49, 16, 48, 96, 160, 240, 336, 448, 64, 18, 54, 108, 180, 270, 378, 504, 648, 81, 20, 60, 120, 200, 300, 420, 560, 720, 900, 100
OFFSET
1,2
COMMENTS
Row sums = A014820: (1, 8, 33, 96, 225, 456, ...).
Denominators of the inverse of A128078: (1/1; 1/4, 1/4; 1/6, 1/18, 1/9; 1/8, 1/24, 1/48, 1/16; ...).
Row sums of this triangle: 1/1, 1/2, 1/3, ...; e.g., (1/8 + 1/24 + 1/48 + 1/16) = 1/4.
FORMULA
Denominators in inverse triangular matrix of A128078, where A128078 = A002260 * A128064, = (1; -1, 4; -1, -2, 9; -1, -2, -3, 16; ...).
EXAMPLE
First few rows of the triangle:
1;
4, 4;
6, 18, 9;
8, 24, 48, 16;
10, 30, 60, 100, 25;
12, 36, 72, 120, 180, 36;
14, 42, 84, 140, 210, 294, 49;
16, 48, 96, 160, 240, 336, 448, 64;
...
Row 4 = (8, 24, 48, 16) = 4 * (2, 6, 12, 4); where (2, 6, 12, 4) = row 4 of A126615.
CROSSREFS
KEYWORD
nonn,tabl,frac
AUTHOR
Gary W. Adamson, Feb 14 2007
STATUS
approved