S001077


Numbers n for which a record number of numbers binomial(n,m) are squarefree, where m <= n/2.

0, 2, 5, 7, 11, 15, 23, 43, 47, 95, 215, 223, 239, 479, 3967, 33119, 84319

1

S001077

Note that only the terms 15, 95, and 215 are composite. Sequence S001078 gives the number of squarefree terms for each n. Is it possible that this sequence is finite?

T. D. Noe, Plot of 16 terms

Wikipedia, Binomial coefficient

(Mma) mx = -1; t = {}; Do[temp = Length[Select[Binomial[n, Range[0, n/2]], SquareFreeQ[#] &]]; If[temp > mx, mx = temp; AppendTo[t, {n, mx}]], {n, 0, 500}]; Transpose[t][[1]]

Cf. A238337, S001078.

nonn,more

T. D. Noe, Jan 25 2018

© Tony D Noe 2014-2018