login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A117906 Inverse of number triangle A117904. 2
1, -1, 1, 0, 0, 1, 0, -1, 0, 1, 0, 0, 0, -1, 1, 0, 0, -1, 0, 0, 1, 0, 0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, -1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Row sums are (1,0,1,0,0,0,...) with g.f. 1+x^2. Diagonal sums are A117907.

LINKS

Table of n, a(n) for n=0..99.

FORMULA

G.f.: (1-x(1-y)+x^2*y^2-x^3*y-x^5*y^2)/(1-x^3*y^3)

EXAMPLE

Triangle begins

1,

-1, 1,

0, 0, 1,

0, -1, 0, 1,

0, 0, 0, -1, 1,

0, 0, -1, 0, 0, 1,

0, 0, 0, 0, -1, 0, 1,

0, 0, 0, 0, 0, 0, -1, 1,

0, 0, 0, 0, 0, -1, 0, 0, 1,

0, 0, 0, 0, 0, 0, 0, -1, 0, 1,

0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1,

0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 1,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 1,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 1

CROSSREFS

Sequence in context: A074910 A115356 A115359 * A090678 A110037 A244528

Adjacent sequences:  A117903 A117904 A117905 * A117907 A117908 A117909

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, Apr 01 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 26 23:05 EST 2020. Contains 331289 sequences. (Running on oeis4.)