OFFSET
1,1
LINKS
Lucas A. Brown, Table of n, a(n) for n = 1..1000
Lucas A. Brown, A355552.py
Index entries for linear recurrences with constant coefficients, signature (2,1,-1,-2,-1,2).
FORMULA
a(n) == H(n) + 3 * D4(n) + 2 * E(n), where
H(n) == 2^(n+2) - 4 - 2*n*(n+1),
D4(n) == floor((n^2 + 2) / 3), and
E(n) == floor((n^2 + 1) / 2).
a(n) ~ 2^(n+2).
G.f.: -x * (6x^4 + 3x^3 - 2x^2 + 5) / ( (x - 1)^2 * (2x^2 + x - 1) * (x^2 + x + 1) ). - Lucas A. Brown, Oct 22 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Thomas Garrison, Jul 14 2022
EXTENSIONS
Corrected and extended by Lucas A. Brown, Oct 20 2022
STATUS
approved