A178244 - OEIS

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A178244

Number of distinct transpositions of binary digits (0s and 1s) in n.

1, 1, 2, 1, 3, 3, 3, 1, 4, 6, 6, 4, 6, 4, 4, 1, 5, 10, 10, 10, 10, 10, 10, 5, 10, 10, 10, 5, 10, 5, 5, 1, 6, 15, 15, 20, 15, 20, 20, 15, 15, 20, 20, 15, 20, 15, 15, 6, 15, 20, 20, 15, 20, 15, 15, 6, 20, 15, 15, 6, 15, 6, 6, 1, 7, 21, 21, 35, 21, 35, 35, 35, 21, 35, 35, 35, 35, 35, 35, 21 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`0,3`
	LINKS	`Table of n, a(n) for n=0..79.`
	FORMULA	`a(n)= binomial ((A000120(n-1)+A023416(n-1)), A000120(n-1)).`
	EXAMPLE	`a(0)=1 because 0 (or 0 written in base 2), a(1)=1 because 1 (or 1 written in base 2), a(3)= 2 (or 10 written in base 2) and (01,10)=distinct transpositions.`
	CROSSREFS	`Cf. A001477.` `Sequence in context: A124770 A099246 A039775 * A152534 A136018 A138022` `Adjacent sequences: A178241 A178242 A178243 * A178245 A178246 A178247`
	KEYWORD	`nonn,base`
	AUTHOR	`Juri-Stepan Gerasimov, May 23 2010`
	EXTENSIONS	`Corrected (a 3 in the first group removed) by R. J. Mathar, May 28 2010`
	STATUS	`approved`

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Last modified May 25 12:15 EDT 2013. Contains 225647 sequences.