OFFSET
1,2
COMMENTS
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,-2,0,-1).
FORMULA
(1, -2, 3, -4, 5,...) interleaved with (1, 2, -2, 2,...) such that the first subsequence starts after the first "2" in the second subsequence.
G.f.: x + x^2*(2+x+2*x^2)/(1+x^2)^2. - R. J. Mathar, Dec 13 2022
MATHEMATICA
Join[{1, 2}, LinearRecurrence[{0, -2, 0, -1}, {1, -2, -2, 2}, 65]] (* Georg Fischer, Nov 02 2021 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Gary W. Adamson, Nov 09 2008
EXTENSIONS
Definition and a(28) ff. corrected by Georg Fischer, Nov 02 2021
STATUS
approved