A186955 1/729 the number of (n+2)X4 0..2 arrays with each 3X3 subblock trace equal to some horizontal or vertical neighbor 3X3 subblock trace

141, 3783, 112707, 3277141, 97400287, 2888274935, 85776954369, 2546947279751, 75630536807503, 2245787022119429, 66687334739920767, 1980238746462258727, 58801972365560118385, 1746088100799717075951, 51849007300503734099607

Offset

1,1

Comments

Column 2 of A186962

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=47*a(n-1)-768*a(n-2)+9074*a(n-3)-45676*a(n-4)-128151*a(n-5)+5533509*a(n-6)-52222861*a(n-7)+298891037*a(n-8)-1210990268*a(n-9)+3279669868*a(n-10)-17103854630*a(n-11)+107074386692*a(n-12)-1120651976017*a(n-13)+7699882976383*a(n-14)-33134456122091*a(n-15)+92437597748240*a(n-16)+38779112318679*a(n-17)-1551804761709560*a(n-18)+9965097308686132*a(n-19)-50284950459235995*a(n-20)+179585137427153085*a(n-21)-578474821841140342*a(n-22)+1942680073913443282*a(n-23)-5027762409706958859*a(n-24)+9396977935434079200*a(n-25)-20206920616774402097*a(n-26)+58961273014571044815*a(n-27)-112421473018387267444*a(n-28)+93462257273423718410*a(n-29)-316402182009678573237*a(n-30)+1531066228189153802915*a(n-31)-2686718460318211032026*a(n-32)+2053586264368753695435*a(n-33)-2076958606567745248818*a(n-34)+1937582374265499138858*a(n-35)+7404451721545153252536*a(n-36)-18194558603000114302344*a(n-37)+9731906357545639525338*a(n-38)-10025123117175587171682*a(n-39)+46821629047289151838716*a(n-40)-45792793514173775732496*a(n-41)-1506342726304390998216*a(n-42)-24094079332639271890128*a(n-43)+74005028615171054189376*a(n-44)-33748481066062903349760*a(n-45)-2412084047728654817280*a(n-46)-29576127381131851372800*a(n-47)+45681436873259623123200*a(n-48)-23580992522523885120000*a(n-49)+5680081947509907840000*a(n-50)-1045093802418288000000*a(n-51)+196518268204272000000*a(n-52)

Example

Some solutions for 6X4
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..0....1..0..0..0....1..0..0..0....0..0..0..0....0..0..0..0
..2..0..0..0....0..0..0..0....1..0..0..0....1..0..0..0....2..0..0..0
..2..1..0..1....0..0..0..1....2..0..1..1....0..0..0..1....1..1..0..0
..1..1..1..1....2..2..2..2....2..0..1..0....1..2..1..1....0..0..0..1
..1..2..1..2....1..2..0..0....1..1..0..0....2..0..0..1....2..1..2..0

Crossrefs

Sequence in context: A204469 A201553 A281560 * A005849 A172633 A221104

Adjacent sequences: A186952 A186953 A186954 * A186956 A186957 A186958

Keyword

nonn

Author

R. H. Hardin Mar 01 2011

Status

approved