cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A181245 T(n,k) = Number of n X k binary matrices with no 2 X 2 circuit having pattern 0101 in any orientation.

Original entry on oeis.org

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
Offset: 1

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Author

R. H. Hardin, Oct 10 2010

Keywords

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

Examples

			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

Main diagonal is A133130.
Column 2 is A055099.
Column 3 is A133129.

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)