A127751 Inverse of number triangle A(n,k)=if(k<=n,if(n<=2k,1/(3n+1),0),0).

1, 0, 4, 0, -4, 7, 0, 4, -7, 10, 0, 0, 0, -10, 13, 0, -4, 7, 0, -13, 16, 0, 0, 0, 0, 0, -16, 19, 0, 4, -7, 10, 0, 0, -19, 22, 0, 0, 0, 0, 0, 0, 0, -22, 25, 0, 0, 0, -10, 13, 0, 0, 0, -25, 28, 0, 0, 0, 0, 0, 0, 0, 0, 0, -28, 31, 0, -4, 7, 0, -13

Offset

0,3

Comments

Row sums A127752 mod 2 are conjectured to be first Feigenbaum symbolic sequence A035263.

Links

Table of n, a(n) for n=0..70.

Example

Triangle begins
  1;
  0,  4;
  0, -4,  7;
  0,  4, -7,  10;
  0,  0,  0, -10,  13;
  0, -4,  7,   0, -13,  16;
  0,  0,  0,   0,   0, -16,  19;
  0,  4, -7,  10,   0,   0, -19,  22;
  0,  0,  0,   0,   0,   0,   0, -22,  25;
  0,  0,  0, -10,  13,   0,   0,   0, -25,  28;
  0,  0,  0,   0,   0,   0,   0,   0,   0, -28,  31;
  0, -4,  7,   0, -13,  16,   0,   0,   0,   0, -31,  34;
  0,  0,  0,   0,   0,   0,   0,   0,   0,   0,   0, -34, 37;
Inverse of
  1;
  0, 1/4;
  0, 1/7, 1/7;
  0,  0,  1/10, 1/10;
  0,  0,  1/13, 1/13, 1/13;
  0,  0,   0,   1/16, 1/16, 1/16;
  0,  0,   0,   1/19, 1/19, 1/19, 1/19;
  0,  0,   0,    0,   1/22, 1/22, 1/22, 1/22;
  0,  0,   0,    0,   1/25, 1/25, 1/25, 1/25, 1/25;
  0,  0,   0,    0,    0,   1/28, 1/28, 1/28, 1/28, 1/28;
  0,  0,   0,    0,    0,   1/31, 1/31, 1/31, 1/31, 1/31, 1/31;

Crossrefs

Sequence in context: A391674 A135011 A184907 * A028602 A111767 A111511

Adjacent sequences: A127748 A127749 A127750 * A127752 A127753 A127754

Keyword

sign,tabl

Author

Paul Barry, Jan 28 2007

Status

approved