OFFSET
1,3
FORMULA
EXAMPLE
a(4)=5; there are two partitions of 4 into two parts: (3,1) and (2,2). The sum of the larger squarefree parts is 3+2=5, thus a(4)=5.
a(5)=3; there are two partitions of 5 into two parts: (4,1) and (3,2). Of the larger parts, 3 is the only squarefree part, so a(5)=3.
MAPLE
MATHEMATICA
Table[Sum[(n - i) MoebiusMu[n - i]^2, {i, Floor[n/2]}], {n, 70}]
PROG
(PARI) a(n) = sum(i=1, n\2, (n-i) * moebius(n-i)^2); \\ Michel Marcus, Oct 04 2015
(PARI) a(n)=my(s); forsquarefree(k=(n+1)\2, n-1, s += k[1]); s \\ Charles R Greathouse IV, Jan 08 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Oct 03 2015
STATUS
approved