OFFSET
0,2
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, 146070, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^18 -4*x^17 +9*x^16 -22*x^15 +31*x^14 -84*x^13 +115*x^12 -314*x^11 +743*x^10 -3286*x^9 -743*x^8 -314*x^7 -115*x^6 -84*x^5 -31*x^4 -22*x^3 -9*x^2 -4*x -1) / (x^20 -146070*x^10 +1). - Colin Barker, Nov 27 2013
a(n) = 146070*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Dec 27 2013
MATHEMATICA
Denominator[Convergents[Sqrt[494], 30]] (* Vincenzo Librandi, Dec 27 2013 *)
LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 146070, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1}, {1, 4, 9, 22, 31, 84, 115, 314, 743, 3286, 145327, 584594, 1314515, 3213624, 4528139, 12269902, 16798041, 45865984, 108530009, 479986020}, 30] (* Harvey P. Dale, May 21 2018 *)
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 27 2013
STATUS
approved