OFFSET
1,2
COMMENTS
MATHEMATICA
cyc[n_] := cyc[n] = Cyclotomic[n, x]; f[n_] := Block[{sd = Take[Subsets@Divisors@n, {2, lmt = 2^(DivisorSigma[0, n] - 1)}], lst = {}, y = x^n - 1}, For[i = 1, i < lmt, i++, pr = Expand[Times @@ (cyc[ # ] & /@ sd[[i]])]; AppendTo[lst, Max@ Abs@ CoefficientList[pr, x]]; AppendTo[lst, Max@ Abs@ CoefficientList[Together[y/pr], x]]]; Max@lst];
t = Array[f, 359]; r = 0; Do[ a = t[[n]]; If[ a > r, Print[{n, a}]; r = a], {n, 359}]
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
Felipe Garcia (fgarciah(AT)ucla.edu) and Robert G. Wilson v, Mar 09 2006
STATUS
approved