login
This site is supported by donations to The OEIS Foundation.

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A119306 Expansion of (1-4x)/(1-x(1-x)^3). 1
1, -3, -6, 6, 14, -19, -37, 56, 96, -164, -247, 477, 630, -1378, -1590, 3957, 3963, -11300, -9728, 32104, 23425, -90771, -55006, 255478, 124758, -715923, -268757, 1997808, 531552, -5552220, -884695, 15368813, 834686, -42373618, 2113458, 116369557, -17926357 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums of number triangle A119305.

LINKS

Table of n, a(n) for n=0..36.

Index to sequences with linear recurrences with constant coefficients, signature (1,-3,3,-1).

FORMULA

G.f.: (1-4x)/(1-x+3x^2-3x^3+x^4); a(n)=a(n-1)-3a(n-2)+3a(n-3)-a(n-4); a(n)=sum{k=0..n, (C(3k,n-k)+4*C(3k,n-k-1))(-1)^(n-k)}.

CROSSREFS

Sequence in context: A202931 A240250 A239424 * A107972 A238775 A036252

Adjacent sequences:  A119303 A119304 A119305 * A119307 A119308 A119309

KEYWORD

easy,sign

AUTHOR

Paul Barry, May 13 2006

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified September 1 03:41 EDT 2014. Contains 246282 sequences.