OFFSET
1,5
FORMULA
a(n) = Sum_{k=1..floor((n-1)/2)} (mu(k)^2 + mu(n-k)^2 - mu(k)^2*mu(n-k)^2), where mu is the Möbius function.
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Feb 21 2022
STATUS
approved