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A252617 Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 3 5 6 or 8 and every 3X3 column and antidiagonal sum not equal to 0 3 5 6 or 8 1
725, 1379, 2815, 6019, 13879, 31514, 71856, 170404, 401865, 928144, 2224005, 5295937, 12290495, 29585255, 70665020, 164351400, 396380374, 947723031, 2206641736, 5326057859, 12737364595, 29676414147, 71648092677, 171334763922 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 2 of A252615

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +48*a(n-3) -48*a(n-4) -939*a(n-6) +939*a(n-7) +9891*a(n-9) -9891*a(n-10) -63231*a(n-12) +63231*a(n-13) +263827*a(n-15) -263827*a(n-16) -759379*a(n-18) +759379*a(n-19) +1583561*a(n-21) -1583561*a(n-22) -2493304*a(n-24) +2493304*a(n-25) +3037897*a(n-27) -3037897*a(n-28) -2885834*a(n-30) +2885834*a(n-31) +2133236*a(n-33) -2133236*a(n-34) -1202312*a(n-36) +1202312*a(n-37) +495108*a(n-39) -495108*a(n-40) -137768*a(n-42) +137768*a(n-43) +20352*a(n-45) -20352*a(n-46) -1152*a(n-48) +1152*a(n-49) for n>52

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A247894 A023680 A002769 * A216618 A185527 A306450

Adjacent sequences:  A252614 A252615 A252616 * A252618 A252619 A252620

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 19 2014

STATUS

approved

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Last modified February 25 12:53 EST 2021. Contains 341607 sequences. (Running on oeis4.)