0,4

Inverse is A166317. Row sums are A012222(n+1). Signed version of A166317.

Triangle begins

1,

0, 1,

-4, 0, 1,

0, -16, 0, 1,

80, 0, -40, 0, 1,

0, 640, 0, -80, 0, 1,

-3904, 0, 2800, 0, -140, 0, 1,

0, -49152, 0, 8960, 0, -224, 0, 1,

354560, 0, -319744, 0, 23520, 0, -336, 0, 1,

0, 6225920, 0, -1454080, 0, 53760, 0, -480, 0, 1,

Production matrix is

0, 1,

-4, 0, 1,

0, -12, 0, 1,

16, 0, -24, 0, 1,

0, 80, 0, -40, 0, 1,

-64, 0, 240, 0, -60, 0, 1,

0, -448, 0, 560, 0, -84, 0, 1,

256, 0, -1792, 0, 1120, 0, -112, 0, 1,

0, 2304, 0, -5376, 0, 2016, 0, -144, 0, 1,

-1024, 0, 11520, 0, -13440, 0, 3360, 0, -180, 0, 1

which is the exponential Riordan array [cos(2x),x] minus its top row.

Sequence in context: A046781 A117435 A117436 this_sequence A166317 A068346 A006838

Adjacent sequences: A166315 A166316 A166317 this_sequence A166319 A166320 A166321

easy,sign,tabl

Paul Barry (pbarry(AT)wit.ie), Oct 11 2009