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A227123 Number of nX4 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X5 binary array having a sum of zero, with rows and columns of the latter in lexicographically nondecreasing order 1
5, 23, 81, 295, 1079, 3836, 12954, 41334, 124956, 359214, 985377, 2587934, 6528298, 15865511, 37249628, 84702904, 186968944, 401441143, 839947739, 1715449948, 3424892827, 6693385156, 12820586861, 24094606746, 44476144089, 80712174607 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A227125

LINKS

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

FORMULA

Empirical: a(n) = (1/121645100408832000)*n^19 + (1/43553562624000)*n^17 + (107/8966909952000)*n^15 + (1/2905943040)*n^14 - (1275569/188305108992000)*n^13 + (23/68428800)*n^12 - (5672753/1379524608000)*n^11 + (191/6220800)*n^10 + (1099466111/1379524608000)*n^9 - (2116283/101606400)*n^8 + (12673870051501/47076277248000)*n^7 - (2627953/1555200)*n^6 + (133732420531/124540416000)*n^5 + (312421343/4276800)*n^4 - (1712634732923/2940537600)*n^3 + (154276843207/75675600)*n^2 - (88924473629/29099070)*n + 944 for n>6

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A211809 A211922 A139209 * A113946 A283114 A290938

Adjacent sequences:  A227120 A227121 A227122 * A227124 A227125 A227126

KEYWORD

nonn

AUTHOR

R. H. Hardin Jul 01 2013

STATUS

approved

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Last modified June 17 07:00 EDT 2019. Contains 324183 sequences. (Running on oeis4.)