login
A041943
Denominators of continued fraction convergents to sqrt(494).
2
1, 4, 9, 22, 31, 84, 115, 314, 743, 3286, 145327, 584594, 1314515, 3213624, 4528139, 12269902, 16798041, 45865984, 108530009, 479986020, 21227914889, 85391645576, 192011206041, 469414057658, 661425263699, 1792264585056, 2453689848755, 6699644282566
OFFSET
0,2
LINKS
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
Sequence in context: A048391 A343322 A041743 * A158140 A290647 A105314
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 27 2013
STATUS
approved