OFFSET
0,2
COMMENTS
For n>2, equal to 2^(n-2) mod 9 [From Michael B. Porter, Feb 02 2010]
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,-1,1).
FORMULA
a(n)=a(n-1)-a(n-3)+a(n-4), n>4. G.f.: (6*x^4+2*x^3+4*x+1-4*x^2)/((1-x)*(1+x)*(x^2-x+1)). [From R. J. Mathar, Feb 25 2009]
MATHEMATICA
Join[{1}, LinearRecurrence[{1, 0, -1, 1}, {5, 1, 2, 4}, 101]] (* Ray Chandler, Jul 15 2015 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Jan 11 2009
EXTENSIONS
Edited by N. J. A. Sloane, Jan 12 2009
Extended by Ray Chandler, Jul 15 2015
STATUS
approved