OFFSET
1,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,12,0,-1).
FORMULA
a(n) = a(n-1)+a(n-2) for n even, a(n) = 10*a(n-1)+a(n-2) for n odd; with a(1) = 2, a(2) = 1.
a(n) = 12*a(n-2)-a(n-4). G.f.: x*(x^3-12*x^2+x+2) / (x^4-12*x^2+1). [Colin Barker, Feb 18 2013]
MATHEMATICA
LinearRecurrence[{0, 12, 0, -1}, {2, 1, 12, 13}, 30] (* Harvey P. Dale, Oct 02 2017 *)
KEYWORD
nonn,easy,less
AUTHOR
Mark Dols, Aug 27 2009
EXTENSIONS
Better name by Paul Muljadi, Jan 13 2011
STATUS
approved