A177963 a(n) = ((prime(n) - 3)!)^2.

1, 4, 576, 1625702400, 13168189440000, 7600054456551997440000, 437763136697395052544000000, 5919012181389927685417441689600000000, 162644002617632464507038883409628607021056000000000000

Offset

2,2

Comments

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.

Links

Nathaniel Johnston, Table of n, a(n) for n = 2..50

Maple

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

Mathematica

((Prime[Range[2, 10]]-3)!)^2 (* Harvey P. Dale, Jun 28 2023 *)

Crossrefs

Cf. A177926.

Sequence in context: A177926 A241095 A343474 * A102201 A102204 A086143

Adjacent sequences: A177960 A177961 A177962 * A177964 A177965 A177966

Keyword

nonn,easy

Author

Giovanni Teofilatto, May 16 2010

Extensions

Offset corrected by Nathaniel Johnston, May 28 2011

Status

approved