OFFSET
0,1
COMMENTS
The least significant digits have a period of length 20. Another period (not the same but of the same length, as this a sequence contains negative numbers) is defined reading the sequence modulo 10.
LINKS
Index entries for linear recurrences with constant coefficients, signature (3,-4,2,-1)
FORMULA
a(n)=4*A105371(n-1), n>0.
a(n)= 3*a(n-1) -4*a(n-2) +2*a(n-3) -a(n-4). G.f.: 4*(1-2*x+2*x^2)/(1-3*x+4*x^2-2*x^3+x^4).
CROSSREFS
KEYWORD
sign
AUTHOR
Paul Curtz, Dec 08 2009
EXTENSIONS
Edited and extended by R. J. Mathar, Mar 02 2010
STATUS
approved