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a(n) = ((prime(n) - 3)!)^2.
1

%I #10 Jun 28 2023 12:01:31

%S 1,4,576,1625702400,13168189440000,7600054456551997440000,

%T 437763136697395052544000000,5919012181389927685417441689600000000,

%U 162644002617632464507038883409628607021056000000000000

%N a(n) = ((prime(n) - 3)!)^2.

%C Except for the first three terms, sqrt(a(n)/400) is an integer. For all terms a(n), sqrt(a(n+1)/a(n)) is an integer.

%H Nathaniel Johnston, <a href="/A177963/b177963.txt">Table of n, a(n) for n = 2..50</a>

%p A177963 := proc(n) return factorial(ithprime(n)-3)^2: end: seq(A177963(n),n=2..10); # _Nathaniel Johnston_, May 28 2011

%t ((Prime[Range[2,10]]-3)!)^2 (* _Harvey P. Dale_, Jun 28 2023 *)

%Y Cf. A177926.

%K nonn,easy

%O 2,2

%A _Giovanni Teofilatto_, May 16 2010

%E Offset corrected by _Nathaniel Johnston_, May 28 2011