A227383 Number of nX4 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X5 binary array having a sum of one, with rows and columns of the latter in lexicographically nondecreasing order

5, 30, 185, 1104, 6160, 31073, 141192, 581706, 2192737, 7631150, 24723499, 75114814, 215382006, 586096131, 1520882101, 3779307010, 9026380556, 20787492011, 46293089506, 99943655427, 209652253128, 428180495383

Offset

1,1

Comments

Column 4 of A227385

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = (1/2534272925184000)*n^19 + (23/800296713216000)*n^18 + (31/29640619008000)*n^17 + (1061/31384184832000)*n^16 + (1/1793792000)*n^15 + (901/89159616000)*n^14 + (573137/7846046208000)*n^13 + (19320181/3621252096000)*n^12 - (25008281/201180672000)*n^11 + (332913253/109734912000)*n^10 - (5757514877/134120448000)*n^9 + (1008987604001/2414168064000)*n^8 - (7198243864451/3923023104000)*n^7 - (144244343741471/11769069312000)*n^6 + (12251347161947/40864824000)*n^5 - (164980284780767/59439744000)*n^4 + (28073158072/1786785)*n^3 - (35127268025713/617512896)*n^2 + (14284038375031/116396280)*n - 121172 for n>7

Example

Some solutions for n=4
..0..1..0..0....1..0..0..0....0..1..0..0....0..0..1..0....0..1..0..0
..1..0..1..1....0..1..0..0....0..0..1..1....1..0..0..0....1..0..0..0
..0..0..1..1....0..0..1..0....0..0..0..1....0..0..0..0....0..1..0..1
..0..0..1..0....0..0..0..1....0..0..1..1....0..1..1..1....0..1..1..1

Crossrefs

Sequence in context: A051738 A052934 A136785 * A155195 A147837 A076036

Adjacent sequences: A227380 A227381 A227382 * A227384 A227385 A227386

Keyword

nonn

Author

R. H. Hardin Jul 09 2013

Status

approved