id:A121601 - OEIS Search Results

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Decimal expansion of cosecant of 22.5 degrees = csc(Pi/8).

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2, 6, 1, 3, 1, 2, 5, 9, 2, 9, 7, 5, 2, 7, 5, 3, 0, 5, 5, 7, 1, 3, 2, 8, 6, 3, 4, 6, 8, 5, 4, 3, 7, 4, 3, 0, 7, 1, 6, 7, 5, 2, 2, 3, 7, 6, 6, 9, 8, 5, 3, 9, 0, 5, 5, 0, 9, 7, 7, 9, 6, 7, 3, 3, 8, 1, 6, 1, 6, 2, 0, 8, 2, 9, 2, 2, 3, 8, 4, 1, 0, 1, 9, 0, 3, 7, 0, 7, 4, 4, 0, 3, 8, 5, 2, 5, 6, 2, 8, 6, 4, 9, 2, 7, 7 (list; cons; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Also, decimal expansion of 2sqrt(2)cos(Pi/8).` `1 + csc(Pi/8) is the radius of the smallest circle into which 9 unit circles can be packed ("r=3.613+ Proved by Pirl in 1969.", according to the Friedman link, which has a diagram). csc(Pi/8) is the distance between the center of the larger circle and the center of each unit circle that touches the larger circle.`
	REFERENCES	`D. Mumford et al., Indra's Pearls, Cambridge 2002; see p. 362. [From njas, Nov 22 2009]`
	EXAMPLE	`2.6131259297527530557132863468543743071675223766985390550977...`
	PROGRAM	`(PARI) 1/sin(Pi/8)`
	CROSSREFS	`Cf. A121598.` `Sequence in context: A024573 A078434 A021892 this_sequence A122761 A100469 A124320` `Adjacent sequences: A121598 A121599 A121600 this_sequence A121602 A121603 A121604`
	KEYWORD	`cons,nonn,new`
	AUTHOR	`Rick L. Shepherd (rshepherd2(AT)hotmail.com), Aug 09 2006`

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.

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