A279257 Numerators of coefficients in expansion of 1/(cos x - sin x).

1, 1, 3, 11, 19, 361, 307, 24611, 83579, 2873041, 12193841, 512343611, 869783713, 11779156811, 769881545161, 44110959165011, 299540369626699, 19450718635716001, 16510282817165209, 10784052561125704811, 8321625562774808569, 7342627959965776406281

Offset

0,3

Links

Clark Kimberling, Table of n, a(n) for n = 0..1000

Example

1/1 + (1/1)x + (3/2)x^2 + (11/6)x^3 + (19/8)x^3 + ... ; 1/1, 1/1, 3/2, 11/6, ... = A279257/A279258.

Mathematica

z = 30; t = CoefficientList[Series[1/(Cos[x] - Sin[x]), {x, 0, z}], x];
Numerator[t]   (* A279257 *)
Denominator[t] (* A279258 *)

Crossrefs

Cf. A279258.

Sequence in context: A192598 A028978 A082628 * A166096 A139220 A139221

Adjacent sequences: A279254 A279255 A279256 * A279258 A279259 A279260

Keyword

nonn,easy,frac

Author

Clark Kimberling, Dec 11 2016

Status

approved