OFFSET
0,3
COMMENTS
Hankel transform of A006134.
Hankel transform of A098479. - Paul Barry, Sep 19 2008
Hankel transform of A025565. - Paul Barry, Mar 26 2010
LINKS
Paul Barry, Jacobsthal Decompositions of Pascal's Triangle, Ternary Trees, and Alternating Sign Matrices, Journal of Integer Sequences, 19, 2016, #16.3.5.
Index entries for linear recurrences with constant coefficients, signature (2,-4).
FORMULA
G.f.: (1-2x)/(1-2x+4x^2).
a(n) = 2^n*(cos(Pi*n/3)-sin(Pi*n/3)/sqrt(3)).
E.g.f.: exp(x)*(cos(sqrt(3)*x) - sin(sqrt(3)*x)/sqrt(3)). - Stefano Spezia, Jul 15 2024
MATHEMATICA
LinearRecurrence[{2, -4}, {1, 0}, 50] (* Harvey P. Dale, Feb 13 2023 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Jun 15 2006
STATUS
approved