OFFSET
1,6
EXAMPLE
a(25) = 17. The squares < 25 are 4, 9 and 16 and the remainders are 1, 7 and 9 and the sum = 17.
MATHEMATICA
a[n_] := Sum[Mod[n, k^2], {k, 1, Floor[Sqrt[n]]}]
Table[Total[Table[Mod[k, n], {n, Range[Floor[Sqrt[k]]]^2}]], {k, 80}] (* Harvey P. Dale, Jan 04 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Jul 31 2002
EXTENSIONS
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 25 2003 and Dean Hickerson, Apr 28 2003
STATUS
approved