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A041745
Denominators of continued fraction convergents to sqrt(392).
2
1, 1, 4, 5, 194, 199, 791, 990, 38411, 39401, 156614, 196015, 7605184, 7801199, 31008781, 38809980, 1505788021, 1544598001, 6139582024, 7684180025, 298138422974, 305822602999, 1215606231971, 1521428834970, 59029901960831, 60551330795801
OFFSET
0,3
FORMULA
G.f.: -(x^2-x-1)*(x^4+5*x^2+1) / ((x^4-14*x^2-1)*(x^4+14*x^2-1)). - Colin Barker, Nov 23 2013
a(n) = 198*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 23 2013
MATHEMATICA
Denominator[Convergents[Sqrt[392], 30]] (* Vincenzo Librandi, Dec 23 2013 *)
PROG
(Magma) I:=[1, 1, 4, 5, 194, 199, 791, 990]; [n le 8 select I[n] else 198*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 23 2013
CROSSREFS
Sequence in context: A101076 A331578 A355705 * A298224 A051152 A042181
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 23 2013
STATUS
approved