login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

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

%I #5 Feb 01 2015 10:39:51

%S 2384,10870,54212,183210,536906,1612832,4205934,10525070,25843648,

%T 60108505,134388526,293848960,621358505,1276346055,2565832463,

%U 5035276195,9660711323,18188928868,33596838971,60932752216,108732023416

%N 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

%C Column 2 of A254568

%H R. H. Hardin, <a href="/A254562/b254562.txt">Table of n, a(n) for n = 1..210</a>

%H R. H. Hardin, <a href="/A254562/a254562.txt">polynomial of degree 20 plus a quasipolynomial of degree 12 with period 6</a>

%F 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

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

%e Some solutions for n=4

%e ..0..0..1..1....0..1..0..1....0..1..0..1....0..0..0..0....0..0..0..0

%e ..1..0..0..1....0..0..0..1....0..0..1..0....0..0..0..1....0..0..0..1

%e ..0..0..1..0....0..0..0..0....1..0..1..1....1..0..0..1....0..0..0..1

%e ..0..1..1..1....0..1..1..1....1..0..1..1....0..0..0..0....1..1..1..0

%e ..1..1..1..1....0..1..1..0....0..0..1..0....0..1..1..1....0..0..1..1

%e ..0..0..1..1....1..0..0..0....1..1..0..1....0..0..1..0....1..1..1..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 01 2015