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

2384, 10870, 54212, 183210, 536906, 1612832, 4205934, 10525070, 25843648, 60108505, 134388526, 293848960, 621358505, 1276346055, 2565832463, 5035276195, 9660711323, 18188928868, 33596838971, 60932752216, 108732023416

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