login
A041505
Denominators of continued fraction convergents to sqrt(269).
2
1, 2, 5, 162, 329, 820, 26569, 53958, 134485, 4357478, 8849441, 22056360, 714652961, 1451362282, 3617377525, 117207443082, 238032263689, 593271970460, 19222735318409, 39038742607278, 97300220532965, 3152645799662158, 6402591819857281, 15957829439376720
OFFSET
0,2
FORMULA
G.f.: -(x^4-2*x^3+5*x^2+2*x+1) / (x^6+164*x^3-1). - Colin Barker, Nov 18 2013
a(n) = 164*a(n-3) + a(n-6) for n>5. - Vincenzo Librandi, Dec 19 2013
MATHEMATICA
Denominator[Convergents[Sqrt[269], 30]] (* Vincenzo Librandi, Dec 19 2013 *)
LinearRecurrence[{0, 0, 164, 0, 0, 1}, {1, 2, 5, 162, 329, 820}, 30] (* Harvey P. Dale, Jan 22 2019 *)
PROG
(Magma) I:=[1, 2, 5, 162, 329, 820]; [n le 6 select I[n] else 164*Self(n-3)+Self(n-6): n in [1..30]]; // Vincenzo Librandi, Dec 19 2013
CROSSREFS
Sequence in context: A062611 A263413 A270585 * A116629 A124275 A013130
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 18 2013
STATUS
approved