OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (40,1).
FORMULA
a(n) = 40*a(n-1)+a(n-2) for n>1, a(0)=20, a(1)=801. G.f.: (20+x)/(1-40*x-x^2). [Philippe Deléham, Nov 23 2008]
MATHEMATICA
Numerator[Convergents[Sqrt[401], 30]] (* Vincenzo Librandi, Nov 07 2013 *)
CROSSREFS
KEYWORD
nonn,cofr,frac,easy,less
AUTHOR
STATUS
approved