A252466 - OEIS

A252466

Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 3 5 6 or 8

570, 716, 1299, 2380, 4507, 8624, 17061, 34876, 71785, 147822, 307470, 642671, 1344403, 2822439, 5937839, 12500966, 26372679, 55715764, 117803237, 249445448, 528853149, 1122332206, 2384791251, 5073248300, 10803996948, 23035159625

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 1 of A252473

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +2*a(n-2) +12*a(n-3) -22*a(n-4) -39*a(n-5) -78*a(n-6) +90*a(n-7) +297*a(n-8) +429*a(n-9) -75*a(n-10) -1158*a(n-11) -1863*a(n-12) -933*a(n-13) +2341*a(n-14) +5351*a(n-15) +4907*a(n-16) -1215*a(n-17) -9007*a(n-18) -11836*a(n-19) -5551*a(n-20) +6301*a(n-21) +14815*a(n-22) +14447*a(n-23) +5681*a(n-24) -5576*a(n-25) -14433*a(n-26) -16716*a(n-27) -10280*a(n-28) +2996*a(n-29) +15135*a(n-30) +16849*a(n-31) +6992*a(n-32) -5730*a(n-33) -10954*a(n-34) -6869*a(n-35) +115*a(n-36) +3502*a(n-37) +2536*a(n-38) +411*a(n-39) -529*a(n-40) -350*a(n-41) -28*a(n-42) +44*a(n-43) +4*a(n-44) -12*a(n-45) -4*a(n-46) for n>55

EXAMPLE

Some solutions for n=4

..3..3..3....1..1..0....0..0..1....1..0..1....1..3..0....1..1..2....0..0..1

..3..1..3....0..3..1....0..1..0....0..1..1....2..1..1....0..0..1....2..0..0

..3..3..3....1..3..0....2..1..1....0..1..0....1..0..0....0..1..1....0..1..1

..3..3..3....0..1..1....0..0..1....2..0..0....1..0..0....2..0..0....0..0..1

..1..3..3....1..0..0....0..0..2....2..1..1....2..1..1....0..1..1....1..1..2

..3..3..1....3..0..1....1..2..1....0..1..1....1..3..0....0..0..1....0..3..1

CROSSREFS

Sequence in context: A221218 A252465 A252473 * A097035 A074907 A231140

Adjacent sequences: A252463 A252464 A252465 * A252467 A252468 A252469

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 17 2014

STATUS

approved