A119832 Bi-diagonal inverse of (3n)!/(3k)!.

1, -6, 1, 0, -120, 1, 0, 0, -504, 1, 0, 0, 0, -1320, 1, 0, 0, 0, 0, -2730, 1, 0, 0, 0, 0, 0, -4896, 1, 0, 0, 0, 0, 0, 0, -7980, 1, 0, 0, 0, 0, 0, 0, 0, -12144, 1, 0, 0, 0, 0, 0, 0, 0, 0, -17550, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, -24360, 1

Offset

0,2

Comments

Row sums are 1-A054776(n). Inverse of A119831.

Links

Table of n, a(n) for n=0..65.

Formula

Column k has g.f. x^k(1-b(k+1)x) where b(n)=3n(3n-2)(3n-1)=A054776(n).

Example

Triangle begins
1,
-6, 1,
0, -120, 1,
0, 0, -504, 1,
0, 0, 0, -1320, 1,
0, 0, 0, 0, -2730, 1,
0, 0, 0, 0, 0, -4896, 1,
0, 0, 0, 0, 0, 0, -7980, 1,
0, 0, 0, 0, 0, 0, 0, -12144, 1,
0, 0, 0, 0, 0, 0, 0, 0, -17550, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, -24360, 1

Crossrefs

Sequence in context: A137388 A302971 A114153 * A166141 A087253 A197686

Adjacent sequences: A119829 A119830 A119831 * A119833 A119834 A119835

Keyword

easy,sign,tabl

Author

Paul Barry, May 25 2006

Status

approved