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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A221664 Sum of neighbor maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to the sum mod 3 of their horizontal, diagonal and antidiagonal neighbors in a random 0..2 nX3 array 1
8, 64, 512, 3772, 32768, 262144, 2097152, 16777216, 134140928, 1073741824, 8589934592, 68719476736, 549755813888, 4398033385216, 35184372088832, 281474976710656, 2251799813685248, 18014398509481984, 144115185909972992 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A221666

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) +360*a(n-5) -2880*a(n-6) -47232*a(n-10) +377856*a(n-11) +2872320*a(n-15) -22978560*a(n-16) -92491776*a(n-20) +739934208*a(n-21) +1689550848*a(n-25) -13516406784*a(n-26) -18150850560*a(n-30) +145206804480*a(n-31) +113850187776*a(n-35) -910801502208*a(n-36) -386547056640*a(n-40) +3092376453120*a(n-41) +549755813888*a(n-45) -4398046511104*a(n-46)

EXAMPLE

Some solutions for n=3

..1..1..1....1..0..0....0..0..1....0..1..1....0..0..1....1..0..0....1..1..0

..0..1..0....0..0..0....0..0..0....0..1..0....0..0..1....1..1..1....1..1..0

..0..0..1....1..1..1....0..1..1....1..0..1....1..0..1....1..1..1....0..0..0

CROSSREFS

Sequence in context: A189155 A189337 A262335 * A228981 A222388 A222937

Adjacent sequences:  A221661 A221662 A221663 * A221665 A221666 A221667

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 21 2013

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 December 1 20:39 EST 2021. Contains 349435 sequences. (Running on oeis4.)