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%I #9 Aug 11 2021 12:55:37
%S 1,4,27,65536,30517578125,22452257707354557240087211123792674816,
%T 54361846697263307560529495055267343940077014163990039113495978834700158362117849904436807
%N n to the power n double factorial, n^(n!!).
%C The next term -- a(8) -- has 347 digits. - _Harvey P. Dale_, Aug 11 2021
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DoubleFactorial.html">Double Factorial</a>
%F a(n) = n^(n!!).
%t Table[n^n!!,{n,7}] (* _Harvey P. Dale_, Aug 11 2021 *)
%o (Python)
%o def doublefactorial(n):
%o if n <= 0:
%o return 1
%o else:
%o return n * doublefactorial(n-2)
%o for n in range(1,m):
%o print(n**doublefactorial(n))
%Y Cf. A254866, A053986.
%K nonn
%O 1,2
%A _Mark Stander_, Mar 20 2019