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!)
A112517 Riordan array (1,x(1+x)(1-x(1+x)). 2
1, 0, 1, 0, 0, 1, 0, -2, 0, 1, 0, -1, -4, 0, 1, 0, 0, -2, -6, 0, 1, 0, 0, 4, -3, -8, 0, 1, 0, 0, 4, 12, -4, -10, 0, 1, 0, 0, 1, 12, 24, -5, -12, 0, 1, 0, 0, 0, -5, 24, 40, -6, -14, 0, 1, 0, 0, 0, -12, -26, 40, 60, -7, -16, 0, 1, 0, 0, 0, -6, -48, -70, 60, 84, -8, -18, 0, 1, 0, 0, 0, -1, -8, -120, -145, 84, 112, -9, -20, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

Riordan array product (1,x(1+x))*(1,x(1-x)). Row sums are A112518. Inverse is A112519.

LINKS

Table of n, a(n) for n=0..90.

FORMULA

Riordan array (1, x(1-2x^2-x^3)); T(n, k)=sum{j=0..n, C(j, n-j)C(k, j-k)(-1)^(j-k)}.

EXAMPLE

Triangle begins

.1;

.0,1;

.0,0,1;

.0,-2,0,1;

.0,-1,-4,0,1;

.0,0,-2,-6,0,1;

CROSSREFS

Sequence in context: A004173 A185370 A066745 * A112519 A276981 A230305

Adjacent sequences:  A112514 A112515 A112516 * A112518 A112519 A112520

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, Sep 09 2005

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 July 10 23:30 EDT 2020. Contains 335600 sequences. (Running on oeis4.)