A056990 - OEIS

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A056990

Number of nonsingular n X n (-1,1)-matrices.

2, 8, 192, 22272, 11550720, 25629327360, 236229525504000, 8858686914082897920, 1331751782100764385607680 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,1`
	LINKS	`Table of n, a(n) for n=1..9.` `Eric Weisstein's World of Mathematics, Nonsingular Matrix.`
	FORMULA	`a(n) = 2^(2n-1) A055165(n-1).`
	CROSSREFS	`Cf. A055165, A056989.` `Sequence in context: A009505 A305737 A028368 * A234637 A234632 A070235` `Adjacent sequences: A056987 A056988 A056989 * A056991 A056992 A056993`
	KEYWORD	`nonn,nice`
	AUTHOR	`Eric W. Weisstein`
	EXTENSIONS	`a(5) from Winston C. Yang (winston(AT)cs.wisc.edu), Aug 26 2000` `a(6)-a(8) computed from A055165 by David desJardins (david(AT)desjardins.org), Apr 22 2001` `a(9) from Max Alekseyev, computed from A055165, Jan 15 2007`
	STATUS	`approved`

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Last modified February 26 17:22 EST 2021. Contains 341632 sequences. (Running on oeis4.)