OFFSET
1,2
COMMENTS
LINKS
EXAMPLE
3 is a term since the arithmetic mean of the first 3 squarefree numbers, (1+2+3)/3 = 2, is an integer.
MATHEMATICA
s = Select[Range[10^6], SquareFreeQ]; r = Accumulate[s]/Range[Length[s]]; ind = Position[r, _?IntegerQ] // Flatten
PROG
(PARI) upto(n) = my(s=0, k=0); forsquarefree(m=1, n, s+=m[1]; k+=1; if(s%k == 0, print1(k, ", "))); \\ Daniel Suteu, Jul 06 2022
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Jul 06 2022
EXTENSIONS
a(17) from Daniel Suteu, Jul 06 2022
STATUS
approved