OFFSET
1,4
COMMENTS
There are really two sequences that should be included if missing: the maximal entry in row c, and the LCM of the entries in row c.
a(n) and the LCM variant A256608(A002808(n)) are equal at least up to n<=1100. - R. J. Mathar, Dec 15 2016
LINKS
R. J. Mathar, Table of n, a(n) for n = 1..1000
Haifeng Xu, The largest cycles consist by the quadratic residues and Fermat primes, arXiv:1601.06509 [math.NT], 2016.
MAPLE
MATHEMATICA
T[n_, k_] := Module[{g, y, r}, If[k == 0, Return[1]]; y = n; g = GCD[k, y]; While[g > 1, y = y/g; g = GCD[k, y]]; If[y == 1, Return[1]]; r = MultiplicativeOrder[k, y]; r = r/2^IntegerExponent[r, 2]; If[r == 1, Return[1]]; MultiplicativeOrder[2, r]]; Composite[n_] := FixedPoint[n + PrimePi[#] + 1&, n + PrimePi[n] + 1];
a[n_] := a[n] = With[{c = Composite[n]}, Table[T[c, k], {k, 0, c-1}] // Max ];
Table[Print["a(", n, ") = ", a[n]]; a[n], {n, 1, 86}] (* Jean-François Alcover, Nov 27 2017, after Robert Israel *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 14 2016
STATUS
approved