OFFSET
1,2
REFERENCES
H. J. S. Smith, Report on the Theory of Numbers, reprinted in Vol. 1 of his Collected Math. Papers, Chelsea, NY, 1979, see p. 322.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
MATHEMATICA
Table[DivisorSigma[1, n]+3DivisorSum[n, Abs[n/#-#]&, #<=Sqrt[n]&], {n, 59}] (* James C. McMahon, Aug 23 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 15 2006
STATUS
approved