OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (3,-1,-1).
FORMULA
a(n) = ((7+4*sqrt(2))*(1+sqrt(2))^n-(7-4*sqrt(2))*(1-sqrt(2))^n)/(2*sqrt(2))-3.
a(n) = 2*a(n-1)+a(n-2)+6 with n>1, a(0)=1, a(1)=8.
a(n) = 3*a(n-1)-a(n-2)-a(n-3). G.f.: (1+5*x)/((1-x)*(1-2*x-x^2)). - Colin Barker, Jun 23 2012
MATHEMATICA
Accumulate[LinearRecurrence[{2, 1}, {1, 7}, 40]] (* Harvey P. Dale, Jul 22 2011 *)
LinearRecurrence[{3, -1, -1}, {1, 8, 23}, 27] (* Ray Chandler, Aug 03 2015 *)
CROSSREFS
KEYWORD
nonn,easy,nice
AUTHOR
EXTENSIONS
More terms from James A. Sellers, Jun 20 2000
STATUS
approved