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, 103682, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: (31 + 94*x + 313*x^2 + 407*x^3 + 720*x^4 + 1847*x^5 + 2567*x^6 + 4414*x^7 + 15809*x^8 + 51841*x^9 + 15809*x^10 - 4414*x^11 + 2567*x^12 - 1847*x^13 + 720*x^14 - 407*x^15 + 313*x^16 - 94*x^17 + 31*x^18 - x^19) / (1 - 103682*x^10 + x^20). - Vincenzo Librandi, Dec 08 2013
a(n) = 103682*a(n-10) - a(n-20). - Vincenzo Librandi, Dec 08 2013
MATHEMATICA
Numerator[Convergents[Sqrt[980], 30]] (* or *) CoefficientList[Series[(31 + 94 x + 313 x^2 + 407 x^3 + 720 x^4 + 1847 x^5 + 2567 x^6+4414 x^7 + 15809 x^8 + 51841 x^9 + 15809 x^10 - 4414 x^11 + 2567 x^12 - 1847 x^13 + 720 x^14 - 407 x^15 + 313 x^16 - 94 x^17 + 31 x^18 - x^19) / (1 - 103682 x^10 + x^20), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 08 2013 *)
PROG
(Magma) I:=[31, 94, 313, 407, 720, 1847, 2567, 4414, 15809, 51841, 3229951, 9741694, 32455033, 42196727, 74651760, 191500247, 266152007, 457652254, 1639108769, 5374978561]; [n le 20 select I[n] else 103682*Self(n-10)-Self(n-20): n in [1..30]]; // Vincenzo Librandi, Dec 08 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Dec 08 2013
STATUS
approved