A309970 Period 12: repeat [1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1].

1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1, 1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1, 1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1, 1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1, 1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1, 1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1, 1, 1, 0, 0, -1, -1

Offset

0

Links

Table of n, a(n) for n=0..77.

Index entries for linear recurrences with constant coefficients, signature (0,1,0,-1).

Formula

a(n) = H(floor((n + 4)/2), 1, 1/2) where H(n, a, b) = hypergeom([a - n/2, b - n/2], [1 - n], 4).

From Chai Wah Wu, Feb 16 2021: (Start)

a(n) = a(n-2) - a(n-4) for n > 3.

G.f.: (1 - x)*(x + 1)^2/(x^4 - x^2 + 1). (End)

Prog

(Magma) &cat [[1, 1, 0, 0, -1, -1, -1, -1, 0, 0, 1, 1]^^10]

Crossrefs

Sequence in context: A188192 A068432 A134668 * A039963 A267537 A329670

Adjacent sequences: A309967 A309968 A309969 * A309971 A309972 A309973

Keyword

sign,easy

Author

Peter Luschny, Sep 03 2019

Status

approved