login
A041044
Numerators of continued fraction convergents to sqrt(28).
2
5, 16, 37, 127, 1307, 4048, 9403, 32257, 331973, 1028176, 2388325, 8193151, 84319835, 261152656, 606625147, 2081028097, 21416906117, 66331746448, 154080399013, 528572943487, 5439809833883, 16848002445136
OFFSET
0,1
FORMULA
a(n) = 254*a(n-4)-a(n-8). G.f.: -(x^7-5*x^6+16*x^5-37*x^4-127*x^3-37*x^2-16*x-5)/((x^4-16*x^2+1)*(x^4+16*x^2+1)). [Colin Barker, Jul 16 2012]
MATHEMATICA
Table[Numerator[FromContinuedFraction[ContinuedFraction[Sqrt[28], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Mar 18 2011 *)
CoefficientList[Series[- (x^7 - 5 x^6 + 16 x^5 - 37 x^4 - 127 x^3 - 37 x^2 - 16 x - 5)/((x^4 - 16 x^2 + 1) (x^4 + 16 x^2 + 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 22 2013 *)
CROSSREFS
Sequence in context: A022496 A372403 A296536 * A042645 A218259 A211807
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved