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A281328
Number of 3Xn 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
1
0, 28, 1266, 21734, 350818, 5192104, 73653131, 1013236400, 13637005631, 180509743938, 2358417603056, 30491748035452, 390836517507309, 4973595490140238, 62904441991868038, 791409380078261316
OFFSET
1,2
COMMENTS
Row 3 of A281326.
LINKS
FORMULA
Empirical: a(n) = 22*a(n-1) -75*a(n-2) -826*a(n-3) +2647*a(n-4) +12524*a(n-5) -31666*a(n-6) -101028*a(n-7) +172228*a(n-8) +478380*a(n-9) -327766*a(n-10) -1371744*a(n-11) -848245*a(n-12) +2223326*a(n-13) +5363769*a(n-14) -723658*a(n-15) -9633470*a(n-16) -5756578*a(n-17) +5497899*a(n-18) +13633286*a(n-19) +3670518*a(n-20) -13409438*a(n-21) -7736445*a(n-22) +6852658*a(n-23) +5255219*a(n-24) -1543628*a(n-25) -2237348*a(n-26) -373776*a(n-27) +751904*a(n-28) +458560*a(n-29) -160320*a(n-30) -151296*a(n-31) +4608*a(n-32) +23552*a(n-33) +11264*a(n-34) -4096*a(n-35) -4096*a(n-36) for n>39
EXAMPLE
Some solutions for n=4
..0..1..1..2. .0..1..2..1. .0..1..1..1. .0..1..2..0. .0..1..2..1
..0..2..2..1. .0..1..2..1. .0..2..0..1. .2..2..0..2. .2..1..1..1
..1..0..1..0. .2..2..0..0. .1..2..0..0. .1..1..2..0. .0..1..0..0
CROSSREFS
Cf. A281326.
Sequence in context: A092705 A061321 A342894 * A091993 A213692 A118705
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 20 2017
STATUS
approved