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%I #16 Feb 23 2024 11:01:26
%S 1,1,0,0,0,0,0,0,1,16,272,2880,32648,333696,3617545,38942336,
%T 443291226,5168682752,63523977424,807890646528,10790865576074,
%U 149552304296960,2168856599259491,32631738808727552,512002155247238968
%N The number of down-up permutations of [n] where adjacent elements differ by at least 4.
%Y Cf. A245377 (at least 2), A249390 (at least 3), A249392-A249393, A179957 (non-alternating).
%K nonn,more
%O 0,10
%A _R. J. Mathar_, Oct 27 2014
%E a(17)-a(20) from _Alois P. Heinz_, Oct 27 2014
%E a(21)-a(24) from _Max Alekseyev_, Feb 18 2024