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A279187 Maximal entry in row c of A279185, where c = n-th composite number A002808(n). 4
1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 4, 1, 4, 2, 6, 2, 1, 1, 4, 1, 2, 2, 6, 2, 1, 2, 4, 2, 10, 1, 6, 4, 1, 2, 6, 4, 2, 6, 3, 1, 4, 2, 1, 2, 4, 1, 10, 2, 2, 6, 4, 6, 4, 2, 1, 18, 4, 2, 1, 6, 3, 4, 2, 2, 10, 4, 11, 6, 1, 6, 4, 4, 1, 2, 2, 12, 6, 4, 6, 2, 6, 10, 3, 2 (list; graph; refs; listen; history; text; internal format)
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

A279187 := proc(n)

    A279186(A002808(n)) ;

end proc :

seq(A279187(n), n=1..180) ; # R. J. Mathar, Dec 15 2016

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-Fran├žois Alcover, Nov 27 2017, after Robert Israel *)

CROSSREFS

Cf. A002808, A256608 (lcm of entries in row n), A279185, A279186 (max entry in row n).

Sequence in context: A025433 A025434 A111178 * A254434 A076845 A161906

Adjacent sequences:  A279184 A279185 A279186 * A279188 A279189 A279190

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 14 2016

STATUS

approved

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Last modified July 29 09:31 EDT 2021. Contains 346344 sequences. (Running on oeis4.)