The On-Line Encyclopedia of Integer Sequences (OEIS)

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A209540

Number of nX5 array permutations with every element making zero or one right-handed knight moves (out 2, right 1)
(history; published version)

#5 by Russ Cox at Sat Mar 31 12:37:29 EDT 2012

AUTHOR

_R. H. Hardin (rhhardin(AT)att.net) _ Mar 10 2012

Discussion

Sat Mar 31

12:37

OEIS Server: https://oeis.org/edit/global/875

#4 by Ron Hardin at Sat Mar 10 10:28:23 EST 2012

STATUS

editing

approved

#3 by Ron Hardin at Sat Mar 10 10:28:20 EST 2012

LINKS

R. H. Hardin, <a href="/A209540/b209540.txt">Table of n, a(n) for n = 1..210</a>

#2 by Ron Hardin at Sat Mar 10 10:27:58 EST 2012

NAME

allocated for Ron HardinNumber of nX5 array permutations with every element making zero or one right-handed knight moves (out 2, right 1)

DATA

1, 8, 243, 6480, 103680, 2080800, 42166080, 833285376, 16312907520, 325995321600, 6453963360000, 127720737849600, 2530106562316032, 50139779258799360, 992798704350478080, 19665530247158611200, 389544838379796084480

OFFSET

1,2

COMMENTS

Column 5 of A209543

FORMULA

Empirical: a(n) = 19*a(n-1) +16*a(n-2) -119472*a(n-5) +2269968*a(n-6) +1911552*a(n-7) +606867456*a(n-10) -11530481664*a(n-11) -9709879296*a(n-12) +125275471872*a(n-15) -2380233965568*a(n-16) -2004407549952*a(n-17) -1099511627776*a(n-20) +20890720927744*a(n-21) +17592186044416*a(n-22) for n>24

EXAMPLE

Some solutions for n=4

..7.10..2..3.13....0..8..2..3.13....0.10..2..3.13....0.10.11.12..4

..5.15..0.17..9....5.15.14.17..9....5..6.14.17.18....5..6.14.17..9

..1.18.19..4.14....1.11.19..4..7....1.11.12..4..7....1..2..3.13..7

..6.16..8.11.12....6.16.10.18.12...15.16..8..9.19...15.16..8.18.19

KEYWORD

allocated

nonn

AUTHOR

R. H. Hardin (rhhardin(AT)att.net) Mar 10 2012

STATUS

approved

editing

#1 by Ron Hardin at Sat Mar 10 10:24:04 EST 2012

NAME

allocated for Ron Hardin

KEYWORD

allocated

STATUS

approved