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!)
A181245 T(n,k)=Number of nXk binary matrices with no 2X2 circuit having pattern 0101 in any orientation 9
2, 4, 4, 8, 14, 8, 16, 50, 50, 16, 32, 178, 322, 178, 32, 64, 634, 2066, 2066, 634, 64, 128, 2258, 13262, 23858, 13262, 2258, 128, 256, 8042, 85126, 275690, 275690, 85126, 8042, 256, 512, 28642, 546410, 3185462, 5735478, 3185462, 546410, 28642, 512, 1024 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

....2......4.........8..........16.............32...............64

....4.....14........50.........178............634.............2258

....8.....50.......322........2066..........13262............85126

...16....178......2066.......23858.........275690..........3185462

...32....634.....13262......275690........5735478........119310334

...64...2258.....85126.....3185462......119310334.......4468252414

..128...8042....546410....36806846.....2481942354.....167341334542

..256..28642...3507314...425288998....51630303190....6267120468434

..512.102010..22512862..4914052362..1074033301458..234710735573170

.1024.363314.144506294.56780001474.22342450688162.8790181730741270

LINKS

R. H. Hardin, Table of n, a(n) for n=1..480

FORMULA

Empirical column 1: a(n)=2*a(n-1)

Empirical column 2: a(n)=3*a(n-1)+2*a(n-2)

Empirical column 3: a(n)=6*a(n-1)+3*a(n-2)-2*a(n-3)

Empirical column 4: a(n)=10*a(n-1)+20*a(n-2)-21*a(n-3)-30*a(n-4)+8*a(n-5)

Empirical column 5: a(n)=21*a(n-1)+9*a(n-2)-278*a(n-3)+73*a(n-4)+790*a(n-5)-662*a(n-6)+29*a(n-7)+69*a(n-8)-10*a(n-9)

Empirical column 6: a(n)=36*a(n-1)+120*a(n-2)-2391*a(n-3)-3905*a(n-4)+50702*a(n-5)+27152*a(n-6)-396016*a(n-7)+154999*a(n-8)+751787*a(n-9)-499260*a(n-10)-410368*a(n-11)+355981*a(n-12)+38077*a(n-13)-70276*a(n-14)+6203*a(n-15)+3386*a(n-16)-622*a(n-17)+28*a(n-18)

Empirical column 7: a(n)=77*a(n-1)-429*a(n-2)-16791*a(n-3)+132938*a(n-4)+1140609*a(n-5)-11250708*a(n-6)-21101443*a(n-7)+356560316*a(n-8)-276630106*a(n-9)-3595865197*a(n-10)+5253257444*a(n-11)+16399879057*a(n-12)-30419637636*a(n-13)-37486637674*a(n-14)+87632998667*a(n-15)+40083109062*a(n-16)-140235056122*a(n-17)-7589163210*a(n-18)+128111780723*a(n-19)-23221600421*a(n-20)-65939015129*a(n-21)+21868944788*a(n-22)+18307048178*a(n-23)-8259596531*a(n-24)-2431120428*a(n-25)+1497147381*a(n-26)+85285300*a(n-27)-123174410*a(n-28)+8581030*a(n-29)+3300116*a(n-30)-512304*a(n-31)+18304*a(n-32)

EXAMPLE

All solutions for 2X2

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

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

...

..1..1....1..1....1..1....1..1

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

CROSSREFS

Diagonal is A133130(n-1)

Column 2 is A055099

Column 3 is A133129

Sequence in context: A047073 A308528 A069753 * A216950 A240364 A225982

Adjacent sequences:  A181242 A181243 A181244 * A181246 A181247 A181248

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Oct 10 2010

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 August 9 22:52 EDT 2020. Contains 336335 sequences. (Running on oeis4.)