A279434 Numerators of coefficients in expansion of 1/(1 + e^x - e^(2x)).

1, 1, 5, 31, 257, 2671, 6661, 484471, 8054177, 150635551, 626067541, 71556251911, 1784401334897, 48205833997231, 280492556837221, 43716593539939351, 1453550100421124417, 51350258701767067711, 384157083636635210101, 530347007443935458537

Offset

0,3

Links

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

Example

(1/1) + (1/1)x + (5/2)x^2 + (31/6)x^3 + ... ; 1/1, 1/1, 5/2, 31/6, ... = A279434/A279435.

Mathematica

z = 20; t = CoefficientList[Series[1/(1 + E^x - E^(2 x)), {x, 0, z}], x]
Numerator[t]    (* A279434 *)
Denominator[t]  (* A279435 *)

Crossrefs

Cf. A279435.

Sequence in context: A291885 A126121 A167137 * A000556 A320512 A125598

Adjacent sequences: A279431 A279432 A279433 * A279435 A279436 A279437

Keyword

nonn,easy,frac

Author

Clark Kimberling, Dec 12 2016

Status

approved