id:A079980 - OEIS Search Results

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Number of permutations of length 2n satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..2n, with k=3, r=3, I={-2,0,1,2}. There is no one such permutation of length 2n+1.

+0
2

1, 0, 1, 2, 3, 8, 12, 27, 52, 95, 196, 369, 720, 1408, 2709, 5292, 10249, 19894, 38675, 74992, 145692, 282823, 549000, 1066095, 2069496, 4018065, 7801024, 15144960, 29404281, 57086680, 110832225, 215178138, 417759539, 811069560, 1574664364 (list; graph; listen)

	OFFSET	`0,4`
	FORMULA	`Recurrence: a(n) = a(n-2)+4a(n-3)+2a(n-4)+2a(n-5)-2a(n-6)+a(n-7)+a(n-9) G.f.: -(x^6-2x^3+1)/(x^9+x^7-2x^6+2x^5+2x^4+4*x^3+x^2-1)`
	CROSSREFS	`Subsequence of A079981.` `Sequence in context: A164817 A002958 A115449 this_sequence A025080 A024468 A134683` `Adjacent sequences: A079977 A079978 A079979 this_sequence A079981 A079982 A079983`
	KEYWORD	`nonn`
	AUTHOR	`Vladimir Baltic (baltic(AT)matf.bg.ac.yu), Feb 17 2003`

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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.

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