A128090 Denominators in inverse of A128077, numerators = 1.

1, -4, 4, -18, -18, 9, -48, -48, -48, 16, -100, -100, -100, -100, 25, -180, -180, -180, -180, -180, 36, -294, -294, -294, -294, -294, -294, 49

Offset: 1

Author

Gary W. Adamson, Feb 14 2007

Keywords

• tabl
• frac
• sign
• more

Comments

Row sums of the inverse of A128077: (1/1; -1/4, 1/4; -1/18, -1/18, 1/9; ...) = (1, 0, 0, 0, ...).

Row sums of unsigned terms: (1; 4, 4; 18, 18, 9; ...) = A128091.

A045991 = (0, 0, 4, 18, 48, 100, ...).

Examples

			First few rows of the triangle:
     1
    -4,    4;
   -18,  -18,    9;
   -48,  -48,  -48,   16;
  -100, -100, -100, -100, 25;
  ...
		

Crossrefs

Cf. A128077, A045991, A128091.

Formula

Denominators in inverse triangular matrix of A128077, i.e., inverse of (1; 1, 4; 1, 2, 9; 1, 2, 3, 16; ...).