OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
FORMULA
Inverse Mobius transform of A004394
EXAMPLE
a(4) = 9 = (1, 1, 0, 1) dot (1, 2, 4, 6) = (1 + 2 + 0 + 6), where (1, 1, 0, 1) = row four of A051731.
MATHEMATICA
sa={}; rm=0; Do[r=DivisorSigma[1, n]/n; If[r>rm, rm=r; AppendTo[sa, n]], {n, 1, 120000}]; s={}; Do[AppendTo[s, DivisorSum[j, sa[[#]]&]], {j, 1, Length[sa]}]; s (* Amiram Eldar, Jun 28 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Gary W. Adamson, Nov 05 2007
EXTENSIONS
More terms from Amiram Eldar, Jun 28 2019
STATUS
approved