A056582 - OEIS

This site is supported by donations to The OEIS Foundation.

A056582

Highest common factor (or GCD) of n^n and hyperfactorial(n-1), i.e. GCD(n^n, product(k^k) for k<n).

1, 1, 4, 1, 1728, 1, 65536, 19683, 3200000, 1, 8916100448256, 1, 13492928512, 437893890380859375, 18446744073709551616, 1, 39346408075296537575424, 1, 104857600000000000000000000 (list; graph; refs; listen; history; internal format)

	OFFSET	`2,3`
	COMMENTS	`Sequence could be defined as: a(2) = 1, a(4) = 4, a(8) = 65536, a(9) = 19683; if p an odd prime: a(p) = 1 and a(2p) = (4p)^p; otherwise if n>1: a(n) = n^n.`
	FORMULA	`a(n) = GCD(A000312(n), A002109(n-1)). Except for n = 4, a(n) = A056583(n)^A056584(n) = A056583(n)^(n^2/A056583(n)) = (n^2/A056584(n))^A056584(n).`
	EXAMPLE	`a(6) = GCD(46656,86400000) = 1728`
	CROSSREFS	`Sequence in context: A038019 A164804 A036115 * A167891 A105087 A028572` `Adjacent sequences: A056579 A056580 A056581 * A056583 A056584 A056585`
	KEYWORD	`nonn,easy`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Jul 03 2000`

Content is available under The OEIS End-User License Agreement .

Last modified February 15 15:20 EST 2012. Contains 205823 sequences.