A154926 Signed version of Pascal's triangle. Diagonal positive, rest negative.

1, -1, 1, -1, -2, 1, -1, -3, -3, 1, -1, -4, -6, -4, 1, -1, -5, -10, -10, -5, 1, -1, -6, -15, -20, -15, -6, 1, -1, -7, -21, -35, -35, -21, -7, 1, -1, -8, -28, -56, -70, -56, -28, -8, 1

Offset

1,5

Comments

Matrix inverse of this lower triangular array is A154921. Signs in columns as in sequence A153881.

Exponential Riordan array [2-exp(x),x]. - Paul Barry, Apr 06 2011

Links

Table of n, a(n) for n=1..45.

Example

From Mats Granvik, Jul 24 2009: (Start)
Table begins:
.1
-1....1
-1...-2....1
-1...-3...-3....1
-1...-4...-6...-4....1
-1...-5..-10..-10...-5....1
-1...-6..-15..-20..-15...-6....1
-1...-7..-21..-35..-35..-21...-7....1
-1...-8..-28..-56..-70..-56..-28...-8....1
-1...-9..-36..-84.-126.-126..-84..-36...-9....1
-1..-10..-45.-120.-210.-252.-210.-120..-45..-10....1
-1..-11..-55.-165.-330.-462.-462.-330.-165..-55..-11....1
(End)

Crossrefs

Cf. A007318, A153881.

Sequence in context: A180183 A273914 A094495 * A117440 A118433 A007318

Adjacent sequences: A154923 A154924 A154925 * A154927 A154928 A154929

Keyword

sign,tabl

Author

Mats Granvik, Jan 17 2009

Status

approved