OFFSET
0,2
COMMENTS
Linear recurrence and g.f. confirmed by Shutov/Maleev link in A301289. - Ray Chandler, Aug 31 2023
LINKS
Ray Chandler, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-5,7,-8,8,-7,5,-3,1).
FORMULA
From Chai Wah Wu, Feb 03 2021: (Start)
a(n) = 3*a(n-1) - 5*a(n-2) + 7*a(n-3) - 8*a(n-4) + 8*a(n-5) - 7*a(n-6) + 5*a(n-7) - 3*a(n-8) + a(n-9) for n > 9.
G.f.: (2*x^9 - 6*x^8 + 4*x^7 - 6*x^6 - 3*x^4 - 4*x^3 - 2*x - 1)/((x - 1)^3*(x^2 + 1)*(x^2 - x + 1)*(x^2 + x + 1)). (End)
MATHEMATICA
Accumulate[LinearRecurrence[{2, -3, 4, -4, 4, -3, 2, -1}, {1, 4, 5, 6, 12, 14, 15, 18, 21, 26}, 100]] (* Harvey P. Dale, Jun 21 2024 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Mar 23 2018
STATUS
approved