A224156 Number of nX6 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.
22, 169, 702, 2271, 6786, 20065, 60214, 184233, 575410, 1833641, 5947567, 19579806, 65205152, 219009930, 740080588, 2511332286, 8545644419, 29133026750, 99436525669, 339656225391, 1160767044395, 3968114261421, 13567722769117
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0..1..1..0....0..0..0..0..0..0....1..0..0..0..0..0....0..0..0..1..0..0 ..0..0..1..1..1..0....0..0..1..1..1..1....0..0..0..0..0..0....1..1..1..1..0..0 ..0..1..1..1..0..0....1..1..1..1..1..1....0..0..0..0..1..0....1..1..1..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 7*a(n-1) -14*a(n-2) +3*a(n-3) +7*a(n-4) +24*a(n-5) -58*a(n-6) +62*a(n-7) -67*a(n-8) +112*a(n-9) -164*a(n-10) +193*a(n-11) -92*a(n-12) -46*a(n-13) +22*a(n-14) -60*a(n-15) -144*a(n-16) +42*a(n-17) -254*a(n-18) -28*a(n-19) -120*a(n-20) -72*a(n-21) +36*a(n-22) -4*a(n-23) +12*a(n-24) for n>27
Comments