A056647 - OEIS

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A056647

Largest unitary square divisor of central binomial coefficient.

1, 1, 1, 1, 1, 4, 1, 1, 9, 36, 1, 4, 4, 1, 9, 9, 1, 4, 1, 4, 4, 1, 1, 4, 100, 25, 100, 25, 9, 144, 9, 9, 1, 4, 25, 100, 100, 25, 9, 36, 4, 1, 4, 1, 25, 400, 225, 900, 1764, 441, 196, 49, 49, 784, 4, 1, 1, 16, 1, 16, 16, 4, 441, 441, 49, 196, 49, 196, 36, 9, 1, 4, 4, 1, 100, 25, 1225 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,6`
	FORMULA	`a(n)=A008833[A001405(n)]/A055229[A001405(n)]^2= A056057(n)/A056059(n)^2`
	EXAMPLE	`n=28, Binomial[28,14]=2.2.2.3.3.3.5.5.17.19.23. Its largest square divisor is 900, while a(28)=900/6^2=25 is the unitary analog, the largest unitary square divisor.`
	CROSSREFS	`A000188, A001405, A055229, A056056, A056057, A056059, A008833.` `Sequence in context: A126065 A126062 A157108 * A056057 A016520 A109955` `Adjacent sequences: A056644 A056645 A056646 * A056648 A056649 A056650`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Aug 09 2000`

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Last modified February 16 02:30 EST 2012. Contains 205860 sequences.