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 A051593 #14 Jun 14 2024 22:31:10
%S A051593 1,1,1,3,3,5,5,7,15,15,21,21,35,35,60,105,105,105,140,210,210,420,420,
%T A051593 420,420,840,1155,1260,1365,1540,2310,2520,4620,4620,5460,5460,9240,
%U A051593 9240,13860,15015,16380,16380,27720,30030,32760,60060,60060,60060
%N A051593 Largest order of even permutation of n elements, or maximal order of element of alternating group A_n.
%D A051593 J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, ATLAS of Finite Groups. Oxford Univ. Press, 1985 [for best online version see https://oeis.org/wiki/Welcome#Links_to_Other_Sites].
%D A051593 V. Jovovic, Some combinatorial characteristics of symmetric and alternating groups (in Russian), Belgrade, 1980, unpublished.
%H A051593 <a href="/index/Gre#groups">Index entries for sequences related to groups</a>
%F A051593 a(n)=max{ A000793(n-2), A051704(n-1), A051704(n) }, a(0)=a(1)=1.
%t A051593 (* a3 = A000793 a4 = A051704 *) a3[n_] := Max[LCM @@@ IntegerPartitions[n]]; a4[n_] := (pp = Reap[ Do[ pk = p^k; If[pk <= n, Sow[pk]], {p, Prime[ Range[2, PrimePi[n]]]}, {k, 1, Ceiling[ Log[3, n]]}]][[2, 1]]; sel = Select[ IntegerPartitions[n, All, pp], Length[#] == Length[ Union[#] && !MatchQ[#, {___, x_, ___, y_, ___} /; GCD[x, y] != 1]] &]; Max[Times @@@ sel]); a4[0] = 1; a4[1] = a4[2] = a4[4] = a4[6] = 0; a[n_] := Max[a3[n - 2], a4[n - 1], a4[n]]; a[0] = a[1] = a[2] = 1; Table[a[n], {n, 0, 47}] (* _Jean-François Alcover_, Sep 11 2012, from formula *)
%o A051593 (PARI) a(n)={my(m=1); forpart(p=n, if(sum(i=1, #p, p[i]-1)%2==0, m=max(m, lcm(Vec(p))))); m} \\ _Andrew Howroyd_, Jul 03 2018
%Y A051593 Cf. A057742, A057743, A057740, A000793.
%K A051593 nonn,nice,easy
%O A051593 0,4
%A A051593 _Vladeta Jovovic_