A251993 Number of (n+2)X(1+2) 0..3 arrays with no row, column, diagonal or antidiagonal in any 3X3 subblock summing to 2 4 5 or 7

1198, 6094, 43572, 340164, 2708560, 21680096, 173871388, 1395137546, 11195863432, 89849246828, 721067681954, 5786805299392, 46441055544156, 372705154430856, 2991084930572790, 24004468769964970, 192643986237872586

Offset

1,1

Comments

Column 1 of A252000

Links

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

Formula

Empirical: a(n) = 11*a(n-1) -26*a(n-2) +37*a(n-3) -205*a(n-4) +376*a(n-5) -230*a(n-6) +1043*a(n-7) -725*a(n-8) -1519*a(n-9) +184*a(n-10) -8070*a(n-11) +14352*a(n-12) -9141*a(n-13) +26804*a(n-14) -17445*a(n-15) +5186*a(n-16) -14288*a(n-17) -9925*a(n-18) +8264*a(n-19) -130*a(n-20) +3216*a(n-21) +7430*a(n-22) -5116*a(n-23) +3318*a(n-24) -1008*a(n-25) -3540*a(n-26) -4*a(n-27) +840*a(n-28) -312*a(n-29) +1008*a(n-30) -384*a(n-31) for n>35

Example

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

Crossrefs

Sequence in context: A059401 A059402 A252000 * A250379 A190833 A351676

Adjacent sequences: A251990 A251991 A251992 * A251994 A251995 A251996

Keyword

nonn

Author

R. H. Hardin, Dec 12 2014

Status

approved