OFFSET
0,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-4).
FORMULA
Binomial transform of A093178: (1, 1, 3, 1, 5, 1, 7, 1...)
a(n) = A129954(n), n>1. G.f.: (1-2x+2x^2-2x^3)/(1-2x)^2. [R. J. Mathar, Dec 13 2008]
a(n) = 2^(n-2)*(n+4) for n>1. - _Colin Barker, Jun 05 2012
EXAMPLE
a(3) = 14 = sum of row 3 terms of triangle A133935: (1 + 3 + 9 + 1); = (1, 3, 3, 1) dot (1, 1, 3, 1).
MATHEMATICA
CoefficientList[Series[(1-2x+2x^2-2x^3)/(1-2x)^2, {x, 0, 40}], x] (* or *) LinearRecurrence[{4, -4}, {1, 2, 6, 14}, 40] (* Harvey P. Dale, Dec 04 2021 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Sep 29 2007
EXTENSIONS
Extended by R. J. Mathar, Dec 13 2008
STATUS
approved