OFFSET
1,2
FORMULA
a(n) = Sum_{i=1..n} (2*n - i) * mu(i)^2, where mu is the Möbius function (A008683).
MATHEMATICA
Table[Sum[(2 n - i) MoebiusMu[i]^2, {i, n}], {n, 80}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Oct 23 2017
STATUS
approved