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%I M3698 #18 May 19 2024 08:05:06
%S 1,4,75,3456,300125,42467328,8931928887,2621440000000,
%T 1025271882697689,515978035200000000,325063112540091870659,
%U 250738401558910243700736,232526248038920243408203125,255326682647558617373989666816,327696095670976278474202880859375,486146690661928563361690196851556352
%N a(n) = n^(n-2)*(n+2)^(n-1).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H T. D. Noe, <a href="/A006236/b006236.txt">Table of n, a(n) for n = 1..100</a>
%H Germain Kreweras, <a href="https://doi.org/10.1016/0095-8956(78)90021-7">Complexité et circuits Eulériens dans les sommes tensorielles de graphes</a>, J. Combin. Theory, B 24 (1978), 202-212.
%t Table[n^(n - 2)*(n + 2)^(n - 1), {n, 20}] (* _T. D. Noe_, May 29 2012 *)
%K nonn
%O 1,2
%A _N. J. A. Sloane_
%E Clarified definition and more terms from _N. J. A. Sloane_, May 27 2012