A204941 Number of (n+2)X3 0..2 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly one way, and new values 0..2 introduced in row major order.

1300, 16032, 196710, 2341863, 28256807, 342322560, 4121107117, 49687384433, 599911304012, 7234956953091, 87258156720963, 1052759849893320, 12699197110951893, 153181763564274981, 1847865787272714872

Offset

1,1

Comments

Column 1 of A204945

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 8*a(n-1) +27*a(n-2) +428*a(n-3) -1312*a(n-4) -9636*a(n-5) +11216*a(n-6) +126210*a(n-7) +145350*a(n-8) -1082254*a(n-9) -3368218*a(n-10) +4598872*a(n-11) +37872901*a(n-12) -826486*a(n-13) -236203557*a(n-14) -149679102*a(n-15) +875933586*a(n-16) +1429448260*a(n-17) -2964984732*a(n-18) -7445745028*a(n-19) +8730419852*a(n-20) +29846253720*a(n-21) -21666810056*a(n-22) -79698500896*a(n-23) +17950685616*a(n-24) +174465701824*a(n-25) -10016088096*a(n-26) -211250504576*a(n-27) +262635065344*a(n-28) -331375100672*a(n-29) -1124771517632*a(n-30) +2096755357504*a(n-31) +1116114033664*a(n-32) -3339876396160*a(n-33) +2328145465344*a(n-34) -1424409134080*a(n-35) -1226396694528*a(n-36) +383552618496*a(n-37) +3339034116096*a(n-38) +2843430486016*a(n-39) -8305528930304*a(n-40) +2381916930048*a(n-41) +2988680675328*a(n-42) -2273757364224*a(n-43) +108716359680*a(n-44)

Example

Some solutions for n=3
..0..0..0....0..1..1....0..0..0....0..0..0....0..0..1....0..0..0....0..0..0
..0..1..0....2..2..2....0..1..0....1..2..2....0..2..1....0..1..1....0..1..2
..2..1..2....1..0..0....2..0..1....1..0..0....1..2..1....1..2..2....1..2..0
..1..1..2....0..0..1....2..0..0....1..1..2....1..2..2....0..0..0....2..2..2
..0..2..2....2..2..2....0..0..2....0..2..1....1..1..0....1..2..1....1..0..2

Crossrefs

Sequence in context: A252468 A135125 A204945 * A022057 A107521 A374803

Adjacent sequences: A204938 A204939 A204940 * A204942 A204943 A204944

Keyword

nonn

Author

R. H. Hardin, Jan 20 2012

Status

approved