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 A127234 a(n) = n! (sum(1..n-1))!. 2
 1, 2, 36, 17280, 435456000, 941525544960000, 257498348545415577600000, 12293098054744302855420641280000000, 134988938425519353794787639744975077376000000000, 434085115076654530026451920435442716425635693068288000000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Number of distinct n x n symmetrical matrices containing A000217(n+1) different elements which have that same trace. LINKS Table of n, a(n) for n=1..10. MATHEMATICA Table[n! (Sum[x, {x, 1, n-1}])!, {n, 1, 10}] Table[n!((n(n-1))/2)!, {n, 10}] (* Harvey P. Dale, May 08 2013 *) CROSSREFS Cf. A127233, A127235. Sequence in context: A308942 A134366 A265944 * A326961 A181555 A306644 Adjacent sequences: A127231 A127232 A127233 * A127235 A127236 A127237 KEYWORD nonn AUTHOR Artur Jasinski, Jan 09 2007, Jan 11 2007 EXTENSIONS Edited by Jason G. Wurtzel, Oct 08 2010 Corrected and extended by Harvey P. Dale, May 08 2013 STATUS approved

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Last modified April 20 21:11 EDT 2024. Contains 371845 sequences. (Running on oeis4.)