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

7, 48, 239, 1084, 4444, 16366, 54500, 166271, 470106, 1243205, 3098315, 7323392, 16507967, 35657274, 74111642, 148760250, 289286122, 546530516, 1005554661, 1805649489, 3170455197, 5452571146, 9198647584, 15243057393, 24840973642

Offset

1,1

Comments

Column 3 of A227103

Links

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

Formula

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

Example

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

Crossrefs

Sequence in context: A292067 A088143 A124880 * A240334 A171312 A186161

Adjacent sequences: A227097 A227098 A227099 * A227101 A227102 A227103

Keyword

nonn

Author

R. H. Hardin Jul 01 2013

Status

approved