A204035 Number of (n+1)X5 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.

286, 1758, 10505, 44366, 189580, 642272, 2198077, 6415866, 18855400, 49463034, 130378965, 316145840, 769485458, 1759764220, 4037835608, 8842012560, 19423451542, 41206754874, 87691553223, 181894892784, 378439038413

Offset: 1

Author

R. H. Hardin Jan 09 2012

Keywords

• nonn

Comments

Column 4 of A204039

Examples

			Some solutions for n=4
..0..0..0..1..1....0..0..1..1..1....1..1..1..0..0....1..0..1..1..0
..0..0..0..1..0....0..1..0..1..1....0..0..0..1..1....0..1..0..1..1
..0..0..1..1..1....0..1..1..1..1....1..1..1..0..1....1..1..1..1..1
..0..0..0..1..1....0..1..1..1..1....1..0..1..1..1....1..1..1..1..1
..0..1..1..1..1....0..1..1..1..1....1..1..1..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) +26*a(n-2) -122*a(n-3) -302*a(n-4) +1766*a(n-5) +1978*a(n-6) -16138*a(n-7) -6930*a(n-8) +104454*a(n-9) +210*a(n-10) -509250*a(n-11) +151130*a(n-12) +1941310*a(n-13) -1020190*a(n-14) -5928050*a(n-15) +4236940*a(n-16) [phone]*a(n-17) -13009090*a(n-18) -30101870*a(n-19) [phone]*a(n-20) [phone]*a(n-21) -61498066*a(n-22) -71033438*a(n-23) [phone]*a(n-24) [phone]*a(n-25) -132597178*a(n-26) -76806422*a(n-27) [phone]*a(n-28) [phone]*a(n-29) -137661898*a(n-30) -32529638*a(n-31) [phone]*a(n-32) [phone]*a(n-33) -68049136*a(n-34) -652352*a(n-35) [phone]*a(n-36) -2735264*a(n-37) -14904960*a(n-38) +2248512*a(n-39) +4904928*a(n-40) -1052352*a(n-41) -1219328*a(n-42) +329216*a(n-43) +215296*a(n-44) -68608*a(n-45) -24064*a(n-46) +8704*a(n-47) +1280*a(n-48) -512*a(n-49)