login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A305178 Number of nX4 0..1 arrays with every element unequal to 1, 2, 5, 6 or 7 king-move adjacent elements, with upper left element zero. 1
2, 1, 9, 10, 13, 47, 71, 118, 241, 453, 870, 1608, 3110, 6075, 11491, 22105, 42831, 82321, 158514, 305836, 589983, 1137829, 2194384, 4234349, 8170446, 15762684, 30415495, 58692610, 113253536, 218539740, 421716458, 813790085, 1570376360 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 4 of A305182.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) -2*a(n-5) -5*a(n-6) -3*a(n-7) -2*a(n-9) +a(n-10) +2*a(n-11) for n>18
EXAMPLE
Some solutions for n=5
..0..1..0..0. .0..1..0..0. .0..0..1..0. .0..0..1..0. .0..1..0..0
..0..0..0..1. .0..0..0..1. .1..0..0..0. .1..0..0..0. .0..0..0..1
..1..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..0. .0..0..0..0
..0..0..0..1. .1..0..1..0. .1..0..0..0. .0..0..0..1. .1..0..0..0
..0..1..0..0. .0..0..0..1. .0..0..1..0. .0..1..0..0. .0..0..1..0
CROSSREFS
Cf. A305182.
Sequence in context: A132744 A059604 A048160 * A295851 A368375 A192324
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 26 2018
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 09:14 EDT 2024. Contains 371268 sequences. (Running on oeis4.)