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A181253 T(n,k)=Number of nXk binary matrices with no 2X2 block having four 1's 8
2, 4, 4, 8, 15, 8, 16, 57, 57, 16, 32, 216, 417, 216, 32, 64, 819, 3032, 3032, 819, 64, 128, 3105, 22077, 42176, 22077, 3105, 128, 256, 11772, 160697, 587920, 587920, 160697, 11772, 256, 512, 44631, 1169792, 8191392, 15701273, 8191392, 1169792, 44631, 512 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

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

....4.....15........57..........216.............819...............3105

....8.....57.......417.........3032...........22077.............160697

...16....216......3032........42176..........587920............8191392

...32....819.....22077.......587920........15701273..........419045269

...64...3105....160697......8191392.......419045269........21418970801

..128..11772...1169792....114142368.....11185495872......1095020802848

..256..44631...8515337...1590466304....298561305103.....55979092539545

..512.169209..61986457..22161786304...7969215344753...2861765993703849

.1024.641520.451223152.308805072256.212714316418464.146298965997241152

LINKS

R. H. Hardin, Table of n, a(n) for n=1..721

FORMULA

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

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

Empirical column 3: a(n)=6*a(n-1)+10*a(n-2)-5*a(n-3)

Empirical column 4: a(n)=10*a(n-1)+54*a(n-2)+16*a(n-3)-64*a(n-4)

Empirical column 5: a(n)=20*a(n-1)+188*a(n-2)-192*a(n-3)-1660*a(n-4)+2804*a(n-5)-507*a(n-6)-624*a(n-7)

Empirical column 6: a(n)=33*a(n-1)+908*a(n-2)+1687*a(n-3)-37947*a(n-4)-16572*a(n-5)+513993*a(n-6)-663729*a(n-7)-486540*a(n-8)+617409*a(n-9)+191835*a(n-10)-49140*a(n-11)

Empirical column 7: a(n)=68*a(n-1)+3106*a(n-2)-10300*a(n-3)-731184*a(n-4)+3930848*a(n-5)+47046600*a(n-6)-471525808*a(n-7)+1012118640*a(n-8)+2396096576*a(n-9)-9445394304*a(n-10)-4382776896*a(n-11)+29415041536*a(n-12)+8676097024*a(n-13)-36065068032*a(n-14)-14871987200*a(n-15)+10138337280*a(n-16)+2907136000*a(n-17)-1119682560*a(n-18)

Empirical column 8: a(n)=113*a(n-1)+13879*a(n-2)+91506*a(n-3)-13567062*a(n-4)-45766270*a(n-5)+5948333641*a(n-6)-25692714697*a(n-7)-932093986319*a(n-8)+9749317949468*a(n-9)+6293344318720*a(n-10)-400364584466276*a(n-11)+544975615003201*a(n-12)+8011657063605359*a(n-13)-12237642139437047*a(n-14)-98976024373360414*a(n-15)+87321080164809042*a(n-16)+743714645681446194*a(n-17)-21941742884172873*a(n-18)-2838216189512832023*a(n-19)-1559534908222727729*a(n-20)+4451110188283146640*a(n-21)+3110756142589939204*a(n-22)-3806251587192837456*a(n-23)-2258950594106495040*a(n-24)+1998716044109621760*a(n-25)+565195437997056000*a(n-26)-541032812384256000*a(n-27)+28184753405952000*a(n-28)+19493777571840000*a(n-29)

CROSSREFS

Diagonal is A139810

Column 2 is A125145

Sequence in context: A282528 A297094 A283282 * A267788 A189696 A189196

Adjacent sequences:  A181250 A181251 A181252 * A181254 A181255 A181256

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Oct 10 2010

STATUS

approved

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Last modified August 22 07:40 EDT 2019. Contains 326172 sequences. (Running on oeis4.)