1,2

Left border (unsigned) = odd indexed Fibonacci numbers. Left border (unsigned) of A123965 = even indexed Fibonacci numbers.

Subtriangle of the triangle T(n,k) given by [0,-2,-1/2,-1/2,0,0,0,0,...] DELTA [1,0,1/2,-1/2,0,0,0,0,0,...] where DELTA is the operator defined in A084938 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Feb 02 2007

A129818*A130595 as lower triangular matrices . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 26 2007

Matrix inverse of A124733.

Sum_{k, 1<=k<=n}(-1)^(n-k)*T(n,k)=A001835(n). - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jul 14 2007

First few rows of the triangle are:

1;

-2, 1;

5, -5, 1;

-13, 19, -8, 1;

34, -65, 42, -11, 1;

-89, 210, -183, 74, -14, 1;

...

Triangle (n>=0 and 0<=k<=n) [0,-2,-1/2,-1/2,0,0,0,0,0,...] DELTA [1,0,1/2,-1/2,0,0,0,0,0,...] begins:

1;

0, 1;

0, -2, 1;

0, 5, -5, 1;

0, -13, 19, -8, 1;

0, 34, -65, 42, -11, 1;

0, -89, 210, -183, 74, -14, 1;

0, 233, -654, 717, -394, 115, -17, 1;

Cf. A123965, A124733.

Adjacent sequences: A126121 A126122 A126123 this_sequence A126125 A126126 A126127

Sequence in context: A033282 A126350 A079502 this_sequence A060920 A107842 A126216

tabl,sign

Gary W. Adamson (qntmpkt(AT)yahoo.com), Dec 17 2006

Corrected by Philippe DELEHAM, Jul 14 2007