OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,99460,0,0,0,0,0,0,0,0,0,-1).
FORMULA
a(n) = 99460*a(n-10)-a(n-20). - Vincenzo Librandi, Nov 08 2013
G.f.: -(x^19 -20*x^18 +61*x^17 -81*x^16 +142*x^15 -223*x^14 +4379*x^13 -4602*x^12 +8981*x^11 -13583*x^10 -49730*x^9 -13583*x^8 -8981*x^7 -4602*x^6 -4379*x^5 -223*x^4 -142*x^3 -81*x^2 -61*x -20) / (x^20 -99460*x^10 +1). - Colin Barker, Dec 28 2013
MATHEMATICA
Numerator[Convergents[Sqrt[411], 30]] (* Vincenzo Librandi, Nov 08 2013 *)
LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 99460, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1}, {20, 61, 81, 142, 223, 4379, 4602, 8981, 13583, 49730, 2002783, 6058079, 8060862, 14118941, 22179803, 435535198, 457715001, 893250199, 1350965200, 4946145799}, 30] (* Vincenzo Librandi, Nov 08 2013 *)
PROG
(Magma) I:=[20, 61, 81, 142, 223, 4379, 4602, 8981, 13583, 49730, 2002783, 6058079, 8060862, 14118941, 22179803, 435535198, 457715001, 893250199, 1350965200, 4946145799]; [n le 20 select I[n] else 99460*Self(n-10)-Self(n-20): n in [1..30]]; // Vincenzo Librandi, Nov 08 2013
CROSSREFS
KEYWORD
nonn,frac,easy,less
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 28 2013
STATUS
approved