|
| |
|
|
A010673
|
|
Period 2: repeat (0,2).
|
|
5
| |
|
|
0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Euler number (or Euler characteristic) of (n+1)-sphere. - Franz Vrabec (franz.vrabec(AT)aon.at), Sep 07 2007
a(n+1) = A167030(n+1)-2*A167030(n). - [From Paul Curtz (bpcrtz(AT)free.fr), Jan 01 2009]
First differences of A109613. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Dec 05 2009]
|
|
|
REFERENCES
| R. Carter, G. Segal, I. Macdonald, Lectures on Lie Groups and Lie Algebras, London Mathematical Society Student Texts 32, Cambridge University Press, 1995; see p. 68.
|
|
|
LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (0,1)
|
|
|
FORMULA
| a(n) = 1-(-1)^n.
a(n) = 2*(n mod 2) - Paolo P. Lava (paoloplava(AT)gmail.com), Oct 20 2006
G.f. -2*x / ((x-1)*(1+x)). - R. J. Mathar, Apr 06 2011
|
|
|
CROSSREFS
| Sequence in context: A021499 A176742 * A084099 A036665 A053472 A036664
Adjacent sequences: A010670 A010671 A010672 * A010674 A010675 A010676
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
| |
|
|
