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A254562 Number of (n+2)X(2+2) 0..1 arrays with every 3X3 subblock sum of the four sums of the central row, central column, diagonal and antidiagonal nondecreasing horizontally and vertically 1
2384, 10870, 54212, 183210, 536906, 1612832, 4205934, 10525070, 25843648, 60108505, 134388526, 293848960, 621358505, 1276346055, 2565832463, 5035276195, 9660711323, 18188928868, 33596838971, 60932752216, 108732023416 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A254568

LINKS

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

R. H. Hardin, polynomial of degree 20 plus a quasipolynomial of degree 12 with period 6

FORMULA

Empirical: a(n) = 7*a(n-1) -20*a(n-2) +41*a(n-3) -105*a(n-4) +246*a(n-5) -414*a(n-6) +708*a(n-7) -1371*a(n-8) +2105*a(n-9) -2834*a(n-10) +4537*a(n-11) -6526*a(n-12) +7449*a(n-13) -9750*a(n-14) +13221*a(n-15) -13299*a(n-16) +13728*a(n-17) -17446*a(n-18) +15730*a(n-19) -11297*a(n-20) +13013*a(n-21) -10296*a(n-22) +1287*a(n-23) -1287*a(n-25) +10296*a(n-26) -13013*a(n-27) +11297*a(n-28) -15730*a(n-29) +17446*a(n-30) -13728*a(n-31) +13299*a(n-32) -13221*a(n-33) +9750*a(n-34) -7449*a(n-35) +6526*a(n-36) -4537*a(n-37) +2834*a(n-38) -2105*a(n-39) +1371*a(n-40) -708*a(n-41) +414*a(n-42) -246*a(n-43) +105*a(n-44) -41*a(n-45) +20*a(n-46) -7*a(n-47) +a(n-48) for n>56

polynomial of degree 20 plus a quasipolynomial of degree 12 with period 6 for n>8 (see link above)

EXAMPLE

Some solutions for n=4

..0..0..1..1....0..1..0..1....0..1..0..1....0..0..0..0....0..0..0..0

..1..0..0..1....0..0..0..1....0..0..1..0....0..0..0..1....0..0..0..1

..0..0..1..0....0..0..0..0....1..0..1..1....1..0..0..1....0..0..0..1

..0..1..1..1....0..1..1..1....1..0..1..1....0..0..0..0....1..1..1..0

..1..1..1..1....0..1..1..0....0..0..1..0....0..1..1..1....0..0..1..1

..0..0..1..1....1..0..0..0....1..1..0..1....0..0..1..0....1..1..1..1

CROSSREFS

Sequence in context: A020394 A251649 A218849 * A186867 A210078 A172653

Adjacent sequences:  A254559 A254560 A254561 * A254563 A254564 A254565

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 01 2015

STATUS

approved

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Last modified September 29 18:27 EDT 2020. Contains 337432 sequences. (Running on oeis4.)