This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A080742 #20 Oct 02 2017 10:54:28
%S A080742 2,6,12,30,60,120,210,420,840,1260,2520,2310,5040,9240,13860,27720,
%T A080742 32760,55440,65520,120120,180180,360360,235620,720720,556920,942480,
%U A080742 1113840,1531530
%N A080742 Largest element of n-th row of A080738.
%H A080742 J. Bamberg, G. Cairns and D. Kilminster, <a href="http://www.jstor.org/stable/3647934">The crystallographic restriction, permutations and Goldbach's conjecture</a>, Amer. Math. Monthly, 110 (March 2003), 202-209.
%t A080742 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-François Alcover_, Jul 24 2013 *)
%o A080742 (Haskell)
%o A080742 a080742 n k = a080742_list !! n
%o A080742 a080742_list = map last a080738_tabf -- _Reinhard Zumkeller_, Jun 13 2012
%Y A080742 Cf. A080737, A080738, A080740, A080741, A005417.
%K A080742 nonn,more
%O A080742 0,1
%A A080742 _N. J. A. Sloane_, Mar 08 2003
%E A080742 Corrected and extended by _Vladeta Jovovic_, Mar 09 2003