A102744 Integers that do not appear in the sequence (A102722) given by the floor of the sum of {n/k} while k=1,...,n. Here {x}:=x-[x].

3, 12, 37, 57, 60, 70, 75, 85, 89, 92, 131, 147, 161, 166, 177, 181, 182, 194, 200, 211, 224, 228, 233, 242, 244, 255, 259, 260, 265, 269, 271, 281, 285, 293, 294, 321, 325, 329, 336, 343, 364, 367, 394, 402, 415, 425, 435, 445, 464, 465, 484, 499, 522, 531

Offset: 1

Author

Carlos Alves, Feb 08 2005

Keywords

• nonn

Crossrefs

Cf. A103504. This is the complement of A102722.

Programs

Mathematica

Resto = Function[n, Sum[n/k - Floor[n/k], {k, 1, n}]]; oops = Floor[Map[Resto, Range[1, 10000]]]; Complement[Range[Max[oops]], Union[oops]]
f[n_] := Floor[Plus @@ FractionalPart[n/Range[2, n - 1]]]; t = {}; Do[ a = f[n]; If[ Position[t, a] == {}, AppendTo[t, a]], {n, 1500}]; Take[ Complement[ Range[ Max[ t]], t], 60] (* Robert G. Wilson v, Feb 19 2005 *)

Extensions

Edited and corrected by Robert G. Wilson v, Feb 19 2005