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A080742 Largest element of n-th row of A080738. 4
2, 6, 12, 30, 60, 120, 210, 420, 840, 1260, 2520, 2310, 5040, 9240, 13860, 27720, 32760, 55440, 65520, 120120, 180180, 360360, 235620, 720720, 556920, 942480, 1113840, 1531530 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..27.

J. Bamberg, G. Cairns and D. Kilminster, The crystallographic restriction, permutations and Goldbach's conjecture, Amer. Math. Monthly, 110 (March 2003), 202-209.

MATHEMATICA

a080737[1] = a080737[2] = 0; a080737[p_?PrimeQ] := a080737[p] = p - 1; a080737[n_] := a080737[n] = If[Length[fi = FactorInteger[n]] == 1, EulerPhi[n], Total[a080737 /@ (fi[[All, 1]]^fi[[All, 2]])]]; orders = Table[{n, a080737[n]}, {n, 1, 2*10^6}]; row[0] = {1, 2}; row[n_] := Select[orders, 2*n - 1 <= #[[2]] <= 2*n &][[All, 1]]; Table[ row[n] // Last, {n, 0, 27}] (* Jean-Fran├žois Alcover, Jul 24 2013 *)

PROG

(Haskell)

a080742 n k = a080742_list !! n

a080742_list = map last a080738_tabf  -- Reinhard Zumkeller, Jun 13 2012

CROSSREFS

Cf. A080737, A080738, A080740, A080741, A005417.

Sequence in context: A056267 A133996 A284573 * A005417 A058215 A330542

Adjacent sequences:  A080739 A080740 A080741 * A080743 A080744 A080745

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Mar 08 2003

EXTENSIONS

Corrected and extended by Vladeta Jovovic, Mar 09 2003

STATUS

approved

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Last modified August 10 16:56 EDT 2020. Contains 336381 sequences. (Running on oeis4.)