A127753 Inverse of number triangle A(n,k) = 1/L(n+1) if k <= n <= 2k, 0 otherwise, where L(n) = A000032(n).

1, 0, 3, 0, -3, 4, 0, 3, -4, 7, 0, 0, 0, -7, 11, 0, -3, 4, 0, -11, 18, 0, 0, 0, 0, 0, -18, 29, 0, 3, -4, 7, 0, 0, -29, 47, 0, 0, 0, 0, 0, 0, 0, -47, 76, 0, 0, 0, -7, 11, 0, 0, 0, -76, 123, 0, 0, 0, 0, 0, 0, 0, 0, 0, -123, 199, 0, -3, 4, 0, -11, 18, 0, 0

Offset

0,3

Comments

Row sums are A127754.

Links

Table of n, a(n) for n=0..73.

Example

Triangle begins
  1;
  0,  3;
  0, -3,  4;
  0,  3, -4,  7;
  0,  0,  0, -7,  11;
  0, -3,  4,  0, -11,  18;
  0,  0,  0,  0,   0, -18,  29;
  0,  3, -4,  7,   0,   0, -29,  47;
  0,  0,  0,  0,   0,   0,   0, -47,  76;
  0,  0,  0, -7,  11,   0,   0,   0, -76,  123;
  0,  0,  0,  0,   0,   0,   0,   0,   0, -123,  199;
  0, -3,  4,  0, -11,  18,   0,   0,   0,    0, -199,  322;
  0,  0,  0,  0,   0,   0,   0,   0,   0,    0,    0, -322, 521;
Inverse of triangle begins
  1;
  0, 1/3;
  0, 1/4, 1/4;
  0,  0,  1/7,  1/7;
  0,  0,  1/11, 1/11, 1/11;
  0,  0,   0,   1/18, 1/18, 1/18;
  0,  0,   0,   1/29, 1/29, 1/29,  1/29;
  0,  0,   0,    0,   1/47, 1/47,  1/47,  1/47;
  0,  0,   0,    0,   1/76, 1/76,  1/76,  1/76,  1/76;
  0,  0,   0,    0,    0,   1/123, 1/123, 1/123, 1/123, 1/123;
  0,  0,   0,    0,    0,   1/199, 1/199, 1/199, 1/199, 1/199, 1/199;

Crossrefs

Cf. A127711.

Sequence in context: A111815 A281269 A210877 * A197736 A073367 A222769

Adjacent sequences: A127750 A127751 A127752 * A127754 A127755 A127756

Keyword

sign,tabl

Author

Paul Barry, Jan 28 2007

Status

approved