A181645 Triangle Id-(xc(x),xc(x)), c(x) the g.f. of the Catalan numbers A000108.

1, -1, 1, -1, -1, 1, -2, -2, -1, 1, -5, -5, -3, -1, 1, -14, -14, -9, -4, -1, 1, -42, -42, -28, -14, -5, -1, 1, -132, -132, -90, -48, -20, -6, -1, 1, -429, -429, -297, -165, -75, -27, -7, -1, 1, -1430, -1430, -1001, -572, -275, -110, -35, -8, -1, 1, -4862, -4862, -3432

Offset

0,7

Comments

Inverse is A181644, the eigentriangle of the Catalan triangle (c(x),xc(x)), A033184.

Links

Table of n, a(n) for n=0..57.

Example

Triangle begins
1,
-1, 1,
-1, -1, 1,
-2, -2, -1, 1,
-5, -5, -3, -1, 1,
-14, -14, -9, -4, -1, 1,
-42, -42, -28, -14, -5, -1, 1,
-132, -132, -90, -48, -20, -6, -1, 1,
-429, -429, -297, -165, -75, -27, -7, -1, 1

Crossrefs

Sequence in context: A123585 A145668 A318405 * A129104 A232648 A295690

Adjacent sequences: A181642 A181643 A181644 * A181646 A181647 A181648

Keyword

easy,sign,tabl

Author

Paul Barry, Nov 03 2010

Status

approved