OFFSET
1,4
FORMULA
a(n) = Sum_{i=1..floor((n-1)/2)} (n-2*i) * mu(n-2*i)^2, where mu is the Möbius function (A008683).
MATHEMATICA
Table[Sum[(n - 2 i) MoebiusMu[n - 2 i]^2, {i, Floor[(n - 1)/2]}], {n, 100}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Apr 19 2018
STATUS
approved