OFFSET
1,1
LINKS
Metin Sariyar, Table of n, a(n) for n = 1..16000
FORMULA
a(n) ~ (Pi^2/(2*Pi^2 - 12)) * n^2. - Amiram Eldar, Oct 21 2020
EXAMPLE
49 is a term because 4, 8, 9, 12, 16 are the first five nonsquarefree numbers and 4 + 8 + 9 + 12 + 16 = 49.
MATHEMATICA
Accumulate[Select[Range[1000], !SquareFreeQ[#]&]]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Metin Sariyar, Nov 13 2019
STATUS
approved