%I #6 May 03 2023 21:36:55
%S 1,0,1,2,18,138,4642,211600,13511246,1092862024,109276859229,
%T 13221974420985,1903936637405380,321762396855180477,
%U 63065061524052355523,14189582409276961769144,3632522968870016652531332,1049797035002712952582167891,340133739324533632977813192678
%N Number of nonisomorphic unordered triples of derangements of an n-set.
%C Isomorphism is up to permutation of the elements of the n-set.
%H Andrew Howroyd, <a href="/A362761/b362761.txt">Table of n, a(n) for n = 0..50</a>
%e The a(3) = 2 nonisomorphic triples of derangements are:
%e {(123), (123), (123)},
%e {(123), (123), (132)}.
%Y Column k=3 of A362759.
%Y Cf. A362646, A362760.
%K nonn
%O 0,4
%A _Andrew Howroyd_, May 02 2023