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A173150
a(n) = sinh^2 (2n*arccosh(sqrt n)).
1
0, 0, 288, 235224, 354079488, 865363202000, 3134808545188320, 15796198853361763368, 105717380511014096025600, 907380314352243226001152800, 9718304978537581699085289156000
OFFSET
0,3
COMMENTS
Also a(n) = -sin(2n*arccos(sqrt(n)))^2 = -sin(2n*arcsin(sqrt(n)))^2.
LINKS
MAPLE
A173150 := proc(n) sinh(2*n*arccosh(sqrt(n))) ; %^2 ; expand(%) ; simplify(%) ; end proc: # R. J. Mathar, Feb 26 2011
MATHEMATICA
Table[Round[-Sin[2 n ArcCos[Sqrt[n]]]^2], {n, 0, 20}] (* Artur Jasinski, Feb 11 2010 *)
KEYWORD
nonn
AUTHOR
Artur Jasinski, Feb 11 2010
EXTENSIONS
Minor edits by Vaclav Kotesovec, Apr 05 2016
STATUS
approved