id:A090915 - OEIS Search Results

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Permutation of natural numbers arising from a spiral.

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1, 8, 7, 6, 5, 4, 3, 2, 9, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 25, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 49, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58 (list; graph; listen)

	OFFSET	`0,2`
	COMMENT	`Write out the natural numbers in a square counter-clockwise spiral:` `17.16.15.14.13` `18..5..4..3.12` `19..6..1..2.11` `20..7..8..9.10` `21.22.23.24.25` `Now read off the numbers in a clockwise spiral: 1 -> 8 -> 7 -> 6 -> 5 -> 4 -> 3 -> 2 -> 9 -> etc.`
	CROSSREFS	`Sequence in context: A104347 A031311 A055119 this_sequence A132672 A132037 A124597` `Adjacent sequences: A090912 A090913 A090914 this_sequence A090916 A090917 A090918`
	KEYWORD	`easy,nonn`
	AUTHOR	`Felix Tubiana (fat2(AT)columbia.edu), Feb 26 2004`

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Last modified December 7 08:40 EST 2009. Contains 170430 sequences.

AT&T Labs Research