OFFSET
0,3
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, 252006, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^18 -x^17 +2*x^16 -15*x^15 +17*x^14 -236*x^13 +253*x^12 -2007*x^11 +2260*x^10 -4267*x^9 -2260*x^8 -2007*x^7 -253*x^6 -236*x^5 -17*x^4 -15*x^3 -2*x^2 -x -1) / ((x^10 -502*x^5 -1)*(x^10 +502*x^5 -1)). - Colin Barker, Dec 21 2013
a(n) = 252006*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Dec 21 2013
MATHEMATICA
Denominator/@Convergents[Sqrt[872], 30] (* Harvey P. Dale, Mar 14 2011 *)
CoefficientList[Series[-(x^18 - x^17 + 2 x^16 - 15 x^15 + 17 x^14 - 236 x^13 + 253 x^12 - 2007 x^11 + 2260 x^10 - 4267 x^9 - 2260 x^8 - 2007 x^7 - 253 x^6 - 236 x^5 - 17 x^4 - 15 x^3 - 2 x^2 - x - 1)/((x^10 - 502 x^5 - 1) (x^10 + 502 x^5 - 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 21 2013 *)
PROG
(Magma) I:=[1, 1, 2, 15, 17, 236, 253, 2007, 2260, 4267, 249746, 254013, 503759, 3780326, 4284085, 59473431, 63757516, 505776043, 569533559, 1075309602]; [n le 20 select I[n] else 252006*Self(n-10)-Self(n-20): n in [1..70]]; // Vincenzo Librandi, Dec 21 2013
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 21 2013
STATUS
approved