OFFSET
0,1
COMMENTS
Related to the Collatz conjecture.
LINKS
Index entries for linear recurrences with constant coefficients, signature (9, -24, 16).
FORMULA
a(n) = ((46-12*n)*4^n-1)/3. - Don Reble, Oct 31 2005
a(0)=15, a(1)=45, a(2)=117, a(n)=9*a(n-1)-24*a(n-2)+16*a(n-3). - Harvey P. Dale, Sep 14 2012
G.f.: ( -15+90*x-72*x^2 ) / ( (x-1)*(-1+4*x)^2 ). - R. J. Mathar, Nov 07 2015
MATHEMATICA
Table[((46-12n)4^n-1)/3, {n, 0, 30}] (* or *) LinearRecurrence[{9, -24, 16}, {15, 45, 117}, 40] (* Harvey P. Dale, Sep 14 2012 *)
CROSSREFS
KEYWORD
sign,easy,less
AUTHOR
N. Rathankar (rathankar(AT)yahoo.com), Jul 08 2002
EXTENSIONS
Edited and extended by David Wasserman, Dec 27 2006
Corrected by N. J. A. Sloane, Mar 01 2007
STATUS
approved