OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..500
FORMULA
MATHEMATICA
midi[n_] := Module[{d = Divisors[n], c, p, m}, c = CoefficientList[Product[1 + x^i, {i, d}], x]; p = -1 + Position[c, _?(# > 0 &)] // Flatten; m = Length[p]; If[OddQ[m], If[(d = p[[(m + 1)/2]] - p[[(m - 1)/2]]) == 1, 0, d], p[[m/2 + 1]] - p[[m/2]]]]; s = {}; Do[m = midi[n]; If[m > 0 && Divisible[n, m], AppendTo[s, n/m]], {n, 1, 2000}]; s (* Amiram Eldar, Dec 11 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Yasutoshi Kohmoto, Jan 01 2007
EXTENSIONS
a(7) corrected and more terms added by Amiram Eldar, Dec 11 2019
STATUS
approved