login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A317764 T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 7
1, 2, 2, 4, 6, 4, 8, 10, 10, 8, 16, 20, 16, 20, 16, 32, 42, 28, 28, 42, 32, 64, 89, 52, 43, 52, 89, 64, 128, 190, 100, 72, 72, 100, 190, 128, 256, 407, 196, 127, 109, 127, 196, 407, 256, 512, 873, 388, 232, 177, 177, 232, 388, 873, 512, 1024, 1874, 772, 432, 302, 266, 302 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Table starts

...1...2...4...8..16...32...64..128..256..512.1024..2048..4096..8192.16384

...2...6..10..20..42...89..190..407..873.1874.4024..8642.18561.39866.85627

...4..10..16..28..52..100..196..388..772.1540.3076..6148.12292.24580.49156

...8..20..28..43..72..127..232..432..813.1539.2922..5557.10577.20141.38362

..16..42..52..72.109..177..302..532..955.1733.3164..5796.10637.19541.35918

..32..89.100.127.177..266..425..709.1217.2126.3753..6666.11882.21223.37952

..64.190.196.232.302..425..639.1012.1663.2801.4792..8278.14385.25088.43852

.128.407.388.432.532..709.1012.1529.2413.3927.6524.10984.18651.31842.54552

.256.873.772.813.955.1217.1663.2413.3674.5798.9381.15434.25672.43007.72386

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..1300

FORMULA

Empirical for column k:

k=1: a(n) = 2*a(n-1)

k=2: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -a(n-4) for n>6

k=3: a(n) = 3*a(n-1) -2*a(n-2) for n>3

k=4: a(n) = 2*a(n-1) +a(n-2) -2*a(n-3) -a(n-4) +a(n-5) for n>6

k=5: a(n) = 2*a(n-1) -a(n-4) for n>6

k=6: a(n) = 2*a(n-1) +a(n-2) -2*a(n-3) -a(n-4) +a(n-7) for n>10

k=7: a(n) = 3*a(n-1) -2*a(n-2) -a(n-4) +a(n-5) -a(n-6) +a(n-7) for n>11

EXAMPLE

Some solutions for n=5 k=4

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

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

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

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

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

CROSSREFS

Column 1 is A000079(n-1).

Column 3 is A003461 for n>1.

Sequence in context: A220358 A089002 A097089 * A318075 A318343 A318024

Adjacent sequences:  A317761 A317762 A317763 * A317765 A317766 A317767

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Aug 06 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 17 18:24 EST 2019. Contains 329241 sequences. (Running on oeis4.)