%I #13 Nov 12 2023 02:52:57
%S 0,2,2,6,34,132,448,1986,8422,39902,195946,1024366,5505428,31185644,
%T 183904498,1119250852,7025176096,45663175776,306194071810,
%U 2107066845486,14874884490258,107949634637898
%N Number of permutations of 1..n with the sum of squared adjacent differences < n*(n-1)/2
%Y Cf. A180068.
%K nonn
%O 2,2
%A _R. H. Hardin_, Aug 09 2010
%E a(17)-a(18) from _Donovan Johnson_, Oct 11 2010
%E a(19)-a(23) from _Martin Ehrenstein_, Nov 12 2023