login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A215868 Number of permutations of 0..floor((n*8-2)/2) on odd squares of an nX8 array such that each row, column, diagonal and (downwards) antidiagonal of odd squares is increasing 1
1, 14, 110, 3001, 26451, 767560, 6812794, 198409297, 1761748159, 51317680568, 455678075546, 13273519382093, 117863060852067, 3433253982499552, 30485799411892266, 888026282079787049, 7885286478349158743 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 8 of A215870

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 272*a(n-2) -3439*a(n-4) -3336*a(n-6) +140*a(n-8)

EXAMPLE

Some solutions for n=4

..x..0..x..2..x..4..x..6....x..0..x..1..x..2..x..7....x..0..x..1..x..3..x..5

..1..x..3..x..7..x..9..x....3..x..4..x..5..x..8..x....2..x..4..x..8..x..9..x

..x..5..x..8..x.10..x.13....x..6..x.10..x.11..x.12....x..6..x.10..x.12..x.14

.11..x.12..x.14..x.15..x....9..x.13..x.14..x.15..x....7..x.11..x.13..x.15..x

CROSSREFS

Sequence in context: A294445 A036395 A271561 * A244693 A039630 A234800

Adjacent sequences:  A215865 A215866 A215867 * A215869 A215870 A215871

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 25 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 6 21:41 EDT 2020. Contains 335483 sequences. (Running on oeis4.)