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A227267 Number of nX4 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X5 binary array having a sum of three or less, with rows and columns of the latter in lexicographically nondecreasing order 1
5, 30, 132, 513, 1949, 7131, 24496, 78761, 238146, 681095, 1852355, 4813290, 11999195, 28801351, 66769946, 149914163, 326768708, 692941231, 1432287640, 2890510485, 5704099317, 11022017108, 20880164204, 38823463828, 70923212058 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A227269

LINKS

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

FORMULA

Empirical: a(n) = (1/121645100408832000)*n^19 + (1/6402373705728000)*n^18 + (23/1067062284288000)*n^17 + (31/62768369664000)*n^16 + (37/5706215424000)*n^15 + (4111/5706215424000)*n^14 - (301079/47076277248000)*n^13 + (126941/452656512000)*n^12 + (14792293/9656672256000)*n^11 - (78942259/877879296000)*n^10 + (13084929349/4828336128000)*n^9 - (165214115519/4828336128000)*n^8 + (5087156753417/23538138624000)*n^7 + (3282017247319/2942267328000)*n^6 - (4087118559803/118879488000)*n^5 + (37821361216913/118879488000)*n^4 - (460675235565641/308756448000)*n^3 + (19317471160409/6175128960)*n^2 + (109108917509/232792560)*n - 9102 for n>7

EXAMPLE

Some solutions for n=4

..1..1..1..1....1..1..1..0....1..1..1..1....1..1..1..1....1..1..1..0

..1..1..1..0....1..1..1..1....1..1..1..1....1..1..0..0....1..1..0..0

..1..0..1..1....0..1..1..1....1..1..0..1....1..0..0..0....1..1..0..0

..0..0..1..1....0..1..1..0....1..1..1..1....1..1..1..1....1..0..0..0

CROSSREFS

Sequence in context: A027173 A286973 A196452 * A213260 A054612 A282078

Adjacent sequences:  A227264 A227265 A227266 * A227268 A227269 A227270

KEYWORD

nonn

AUTHOR

R. H. Hardin Jul 04 2013

STATUS

approved

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Last modified August 14 03:14 EDT 2022. Contains 356109 sequences. (Running on oeis4.)