A043551 Least k for which the integers floor(4*k/m) for m=2,3,...,n are distinct.

1, 1, 1, 3, 3, 4, 5, 9, 11, 14, 16, 23, 25, 31, 33, 39, 46, 49, 60, 64, 68, 81, 86, 95, 105, 116, 121, 138, 144, 157, 169, 183, 189, 203, 218, 233, 248, 256, 281, 289, 307, 324, 333, 361, 371, 390, 410, 431, 452, 473, 484, 518, 529

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Crossrefs

Cf. A043549, A043550, A043552.

Programs

Mathematica

lkid[n_]:=Module[{k=1},While[Max[Tally[Floor[(4k)/Range[2,n]]][[All, 2]]]> 1,k++];k]; Array[lkid,60] (* Harvey P. Dale, Jun 18 2018 *)

PARI

a(n) = my(k=1); while(#Set(vector(n-1, m, 4*k\(m+1))) != n-1, k++); k; \\ Michel Marcus, Apr 26 2021