OFFSET
1,2
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..150
EXAMPLE
a(12) = 18 because 1 + 1/2 + ... + 1/17 < sqrt(12) < 1 + 1/2 + ... + 1/18.
MATHEMATICA
z = 80; f[n_] := 1/n; Do[s = 0; a[n] = NestWhile[# + 1 &, 1, ! (s += f[#]) >= Sqrt[n] &], {n, 1, z}]; m = Map[a, Range[z]]
Table[Ceiling[x /. FindInstance[HarmonicNumber[x] == Sqrt[n] && x > 0, x][[1]]], {n, 80}] (* Vladimir Reshetnikov, Aug 06 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 30 2013
STATUS
approved