A252441 Number of (n+2)X(1+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum less than 3

339, 1677, 9062, 48658, 259257, 1382414, 7389034, 39505162, 211085078, 1127932908, 6027956200, 32214103236, 172151883337, 919985137034, 4916449385076, 26273721744552, 140407834691944, 750345450048779

Offset

1,1

Comments

Column 1 of A252447

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +8*a(n-2) +41*a(n-3) +68*a(n-4) +33*a(n-5) -207*a(n-6) -543*a(n-7) -471*a(n-8) -30*a(n-9) +202*a(n-10) -352*a(n-11) -548*a(n-12) +37*a(n-13) +640*a(n-14) +670*a(n-15) +347*a(n-16) +235*a(n-17) -124*a(n-18) -97*a(n-19) -106*a(n-20) -51*a(n-21) -56*a(n-22) +8*a(n-23) +4*a(n-24) +8*a(n-25) +4*a(n-27) for n>29

Example

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

Crossrefs

Sequence in context: A235880 A158000 A252447 * A236896 A076748 A306865

Adjacent sequences: A252438 A252439 A252440 * A252442 A252443 A252444

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved