A204034 Number of (n+1)X4 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.
121, 603, 2928, 10505, 37642, 111578, 330509, 863435, 2254026, 5394662, 12906149, 29037224, 65337510, 140736855, 303340170, 634000207, 1326522462, 2717180447, 5573314419, 11270539628, 22825534613, 45808619416, 92067615036, 184020632660
Offset: 1
Keywords
Examples
Some solutions for n=4 ..1..0..0..0....1..1..0..0....1..0..1..1....0..0..1..1....0..0..0..0 ..0..0..1..0....0..0..1..1....0..1..1..0....1..1..0..0....0..1..0..1 ..0..1..1..1....1..1..1..1....1..0..1..1....0..0..1..1....1..1..1..1 ..0..1..1..1....0..0..1..1....0..1..1..1....1..1..0..0....1..0..1..0 ..1..1..1..1....1..1..1..1....0..1..1..1....0..0..1..1....1..1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 4*a(n-1) +20*a(n-2) -98*a(n-3) -168*a(n-4) +1122*a(n-5) +674*a(n-6) -7970*a(n-7) -205*a(n-8) +39322*a(n-9) -13326*a(n-10) -142896*a(n-11) +86380*a(n-12) +395612*a(n-13) -325028*a(n-14) -850708*a(n-15) +867429*a(n-16) +1433880*a(n-17) -1752520*a(n-18) -1894178*a(n-19) +2759240*a(n-20) +1938970*a(n-21) -3430470*a(n-22) -1491450*a(n-23) +3380665*a(n-24) +795530*a(n-25) -2631230*a(n-26) -214060*a(n-27) +1599540*a(n-28) -65400*a(n-29) -744088*a(n-30) +104272*a(n-31) +255920*a(n-32) -56864*a(n-33) -61344*a(n-34) +17856*a(n-35) +9152*a(n-36) -3200*a(n-37) -640*a(n-38) +256*a(n-39)
Comments