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 A227100 Number of nX3 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X4 binary array having a sum of two, with rows and columns of the latter in lexicographically nondecreasing order 1

%I

%S 7,48,239,1084,4444,16366,54500,166271,470106,1243205,3098315,7323392,

%T 16507967,35657274,74111642,148760250,289286122,546530516,1005554661,

%U 1805649489,3170455197,5452571146,9198647584,15243057393,24840973642

%N Number of nX3 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X4 binary array having a sum of two, with rows and columns of the latter in lexicographically nondecreasing order

%C Column 3 of A227103

%H R. H. Hardin, <a href="/A227100/b227100.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (1/1307674368000)*n^15 + (1/10897286400)*n^14 + (73/18681062400)*n^13 + (47/479001600)*n^12 + (713/326592000)*n^11 + (407/14515200)*n^10 + (170281/914457600)*n^9 + (790477/304819200)*n^8 + (1304149/186624000)*n^7 + (894611/43545600)*n^6 + (392782843/718502400)*n^5 + (120032611/39916800)*n^4 - (26912769857/756756000)*n^3 + (7313782601/50450400)*n^2 - (8615569/32760)*n + 352 for n>5

%e Some solutions for n=4

%e ..0..1..0....0..0..0....0..1..1....1..0..0....0..1..0....0..0..0....0..0..0

%e ..1..0..0....1..1..1....1..0..0....1..0..0....1..0..0....0..0..1....0..1..1

%e ..0..0..1....0..0..0....0..1..1....1..1..1....1..0..0....1..1..1....1..1..0

%e ..0..0..1....0..1..0....0..1..0....0..1..1....0..1..0....0..1..1....1..0..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Jul 01 2013

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Last modified March 26 19:25 EDT 2023. Contains 361552 sequences. (Running on oeis4.)