A186554 Number of (n+1)X2 0..3 arrays with no 2X2 subblock commuting with any of its horizontal and vertical 2X2 subblock neighbors.
256, 3891, 60074, 927477, 14319230, 221073168, 3413126694, 52694924343, 813551707879, 12560344087053, 193917905964431, 2993879307207532, 46222205533558883, 713620044483130375, 11017509052404905567
Offset: 1
Keywords
Examples
Some solutions for 3X2 ..2..1....3..3....0..3....1..3....3..1....2..0....1..0....0..2....1..1....3..2 ..0..1....2..2....0..0....2..1....0..1....3..2....1..3....0..3....1..3....3..2 ..3..2....0..2....2..0....1..1....2..0....2..0....3..0....2..2....3..2....0..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Formula
Empirical: a(n)=4*a(n-1)+104*a(n-2)+797*a(n-3)+3891*a(n-4)+14095*a(n-5)+40200*a(n-6)+92485*a(n-7)+171998*a(n-8)+252349*a(n-9)+268492*a(n-10)+139234*a(n-11)-161414*a(n-12)-521070*a(n-13)-687529*a(n-14)-423636*a(n-15)+253948*a(n-16)+987357*a(n-17)+1330329*a(n-18)+1183644*a(n-19)+932235*a(n-20)+994269*a(n-21)+1201760*a(n-22)+856341*a(n-23)-350728*a(n-24)-1594116*a(n-25)-1551129*a(n-26)-10297*a(n-27)+1532661*a(n-28)+1395959*a(n-29)-294208*a(n-30)-1710585*a(n-31)-1500735*a(n-32)-230622*a(n-33)+624783*a(n-34)+502770*a(n-35)+14161*a(n-36)-185750*a(n-37)-87729*a(n-38)+20841*a(n-39)+32262*a(n-40)+10922*a(n-41)+3426*a(n-42)+3024*a(n-43)+1107*a(n-44)-285*a(n-45)-255*a(n-46)-34*a(n-47)+3*a(n-48) for n>49
Comments