OFFSET
1,5
LINKS
FORMULA
a(n) = n * Sum_{i=1..floor(n/2)} (1 - mu(n-i)^2), where mu is the Möbius function (A008683).
MATHEMATICA
Table[n*Sum[(1 - MoebiusMu[n - k]^2), {k, Floor[n/2]}], {n, 80}]
PROG
(PARI) a(n) = n*sum(i=1, n\2, 1-moebius(n-i)^2); \\ Michel Marcus, Feb 11 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Oct 25 2017
STATUS
approved