A274952 Expansion of (4+x-x^2+x^3-x^4+x^5) / (1-3*x-x^2+x^3-x^4+x^5-x^6).

4, 13, 42, 136, 440, 1424, 4609, 14918, 48285, 156284, 505844, 1637264, 5299328, 17152321, 55516872, 179691313, 581606398, 1882483892, 6093030640, 19721296176, 63831867233, 206604436042, 668716032329, 2164431415224, 7005609443656, 22675037578848, 73392234228496, 237548450639617, 768872442629260

Offset

0,1

Comments

Coincides with the Pisot sequence A010900 just for n <= 23.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3,1,-1,1,-1,1).

Formula

Recurrence: a(n) = 3*a(n-1) + a(n-2) - a(n-3) + a(n-4) - a(n-5) + a(n-6).

Mathematica

CoefficientList[Series[(4 + x - x^2 + x^3 - x^4 + x^5) / (1 - 3 x - x^2 + x^3 - x^4 + x^5 - x^6), {x, 0, 40}], x] (* Vincenzo Librandi, Aug 18 2016 *)
LinearRecurrence[{3, 1, -1, 1, -1, 1}, {4, 13, 42, 136, 440, 1424}, 40] (* Harvey P. Dale, Feb 15 2020 *)

Crossrefs

Cf. A008776, A010900.

Sequence in context: A022029 A010919 A277667 * A010900 A175005 A070031

Adjacent sequences: A274949 A274950 A274951 * A274953 A274954 A274955

Keyword

nonn

Author

N. J. A. Sloane, Aug 07 2016

Status

approved