OFFSET
1,1
COMMENTS
FORMULA
a(n) = 1 + Sum_{k=1..2*n} sign((sign(n+Sum_{j=2..k}-|A309229(n,j)|)+1)).
MATHEMATICA
nn = 68; f[n_] := n; h[n_] := DivisorSum[n, MoebiusMu[#] # &]; A = Accumulate[Table[Table[h[GCD[n, k]], {k, 1, nn}], {n, 1, nn}]]; B = -Abs[A]; B[[All, 1]] = Table[f[n], {n, 1, nn}]; b = 1 + Total[Sign[1 + Sign[Accumulate[Transpose[B]]]]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Mats Granvik, Jun 09 2020
STATUS
approved