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, 2403774, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^18 -3*x^17 +7*x^16 -17*x^15 +92*x^14 -569*x^13 +2937*x^12 -6443*x^11 +15823*x^10 -53912*x^9 -15823*x^8 -6443*x^7 -2937*x^6 -569*x^5 -92*x^4 -17*x^3 -7*x^2 -3*x -1) / (x^20 -2403774*x^10 +1). - Colin Barker, Nov 27 2013
a(n) = 2403774*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Dec 27 2013
MATHEMATICA
Denominator[Convergents[Sqrt[497], 30]] (* Vincenzo Librandi, Dec 27 2013 *)
PROG
(Magma) I:=[1, 3, 7, 17, 92, 569, 2937, 6443, 15823, 53912, 2387951, 7217765, 16823481, 40864727, 221147116, 1367747423, 7059884231, 15487515885, 38034916001, 129592263888]; [n le 20 select I[n] else 2403774*Self(n-10)-Self(n-20): n in [1..40]]; // Vincenzo Librandi, Dec 27 2013
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 27 2013
STATUS
approved