A203794 Number of (n+1)X7 0..3 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements

1882384, 345682576, 72168659104, 15768587718160, 3504288958063120, 783865714144759744, 175775764083051254128, 39454255487228836622320, 8859012529154013233323456, 1989474806613853504987401904

Offset

1,1

Comments

Column 6 of A203796

Links

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

Formula

Empirical: a(n) = 208*a(n-1) +17400*a(n-2) -3283416*a(n-3) +23420421*a(n-4) +5886581850*a(n-5) -83228590584*a(n-6) -3526251031431*a(n-7) +57850559193204*a(n-8) +782023861525509*a(n-9) -14739518837987658*a(n-10) -60641138261637936*a(n-11) +1598662604889997434*a(n-12) +238856341604935320*a(n-13) -76586199580277604432*a(n-14) +119784669306218825400*a(n-15) +1667672399025022092660*a(n-16) -3846520848128975062668*a(n-17) -16550563018684070626632*a(n-18) +43676894398326611425920*a(n-19) +69929164554171688755288*a(n-20) -199117214696190701946528*a(n-21) -104062366058720357995200*a(n-22) +320309318149377624589824*a(n-23) +62868535445891985578496*a(n-24) -158787620907305349641472*a(n-25) -9126122457607434141696*a(n-26) +19192360132970190176256*a(n-27) -2161923504213443346432*a(n-28)

Example

Some solutions for n=4
..3..1..1..2..1..1..2....1..1..0..1..1..1..3....1..2..3..2..3..1..1
..1..3..1..1..1..0..1....2..1..1..2..1..3..3....1..1..2..3..1..3..1
..1..1..1..1..2..1..3....2..2..1..1..3..2..3....3..1..1..2..3..1..3
..0..1..3..1..1..3..3....2..3..2..1..1..3..1....2..3..1..1..2..3..1
..3..0..1..0..1..1..3....1..2..1..3..1..1..3....2..2..3..1..1..2..3

Crossrefs

Sequence in context: A230806 A032596 A032597 * A204672 A323705 A249318

Adjacent sequences: A203791 A203792 A203793 * A203795 A203796 A203797

Keyword

nonn

Author

R. H. Hardin Jan 05 2012

Status

approved