login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A090133 Expansion of (1+4x)/(1+4x+5x^2). 0
1, 0, -5, 20, -55, 120, -205, 220, 145, -1680, 5995, -15580, 32345, -51480, 44195, 80620, -543455, 1770720, -4365605, 8608820, -12607255, 7384920, 33496595, -170910980, 516160945, -1210088880, 2259550795, -2987758780, 653281145, 12325669320 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

D. Cvijovic, J Klinowski, An Application for the Chebyshev Polynomials, Mat. Vesnik 50 (1998) 105-110

LINKS

Table of n, a(n) for n=0..29.

D. Cvijovic and J. Klinowski, An Application for the Chebyshev Polynomials, Mat. Vesnik 50 (1998) 105-110.

Index entries for linear recurrences with constant coefficients, signature (-4,-5).

FORMULA

a(n)=sum{k=0..n, C(n, k)(-2)^(n-k)(-1)^floor(k/2)(1+(1-(-1)^k)/2) }

a(n+1) = (-1)^n * (4*A099456(n) - A099456(n+1)). - Ralf Stephan, Jul 19 2013

CROSSREFS

Sequence in context: A270334 A008524 A055383 * A351931 A289306 A325731

Adjacent sequences:  A090130 A090131 A090132 * A090134 A090135 A090136

KEYWORD

easy,sign

AUTHOR

Paul Barry, Nov 21 2003

EXTENSIONS

Better name from Ralf Stephan, Jul 14 2013

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 1 21:18 EDT 2022. Contains 357173 sequences. (Running on oeis4.)