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A186245 a(n) = binomial(n^2, 2*n). 1

%I #19 May 22 2021 04:26:58

%S 1,84,12870,3268760,1251677700,675248872536,488526937079580,

%T 456703981505085600,535983370403809682970,771629762387959506903300,

%U 1337261858854117218288723600,2746379593275133584459064976784,6596095888094645606758451183394760

%N a(n) = binomial(n^2, 2*n).

%H Michael De Vlieger, <a href="/A186245/b186245.txt">Table of n, a(n) for n = 2..205</a>

%t Array[Binomial[#^2, 2 #] &, 13, 2] (* _Michael De Vlieger_, May 21 2021 *)

%o (Python)

%o import math

%o for n in range(2,22):

%o x = n*n

%o y = n+n

%o print(math.factorial(x) / (math.factorial(x-y) * math.factorial(y)), end=',')

%Y Cf. A014062.

%K nonn

%O 2,2

%A _Alex Ratushnyak_, Aug 18 2012

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)