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 A183680 T(n,k)=Number of (n+1)X(k+1) 0..7 arrays with every 2X2 subblock summing to 14 8
 344, 2080, 2080, 13448, 10088, 13448, 90784, 54496, 54496, 90784, 631784, 316232, 252920, 316232, 631784, 4497760, 1931680, 1287136, 1287136, 1931680, 4497760, 32592008, 12267368, 7003928, 5836328, 7003928, 12267368, 32592008, 239551264 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Table starts .........344.......2080......13448.....90784....631784...4497760..32592008 ........2080......10088......54496....316232...1931680..12267368..80331616 .......13448......54496.....252920...1287136...7003928..40112416.239241080 .......90784.....316232....1287136...5836328..28648864.149494472.819074656 ......631784....1931680....7003928..28648864.128141624.614337760 .....4497760...12267368...40112416.149494472.614337760 ....32592008...80331616..239241080.819074656 ...239551264..539328392.1474919776 ..1781373224.3696942880 .13376585440 LINKS R. H. Hardin, Table of n, a(n) for n = 1..59 FORMULA Empirical, for every row and column: a(n)=36*a(n-1)-546*a(n-2)+4536*a(n-3)-22449*a(n-4)+67284*a(n-5)-118124*a(n-6)+109584*a(n-7)-40320*a(n-8) The coefficient of a(n-i) is -s(9,9-i), s() being the Stirling number of the first kind, via D. S. McNeil and M. F. Hasler in the Sequence Fans Mailing List. For a 0..z array with 2X2 blocks summing to 2z, the coefficients are -s(z+2,z+2-i) EXAMPLE Some solutions for 4X3 ..7..0..7....3..6..4....5..3..3....6..3..2....7..0..5....1..5..0....2..5..2 ..1..6..1....4..1..3....5..1..7....3..2..7....3..4..5....6..2..7....0..7..0 ..5..2..5....5..4..6....7..1..5....4..5..0....6..1..4....6..0..5....3..4..3 ..1..6..1....3..2..2....2..4..4....2..3..6....1..6..3....1..7..2....1..6..1 CROSSREFS Sequence in context: A236090 A237378 A237243 * A183674 A245994 A246630 Adjacent sequences:  A183677 A183678 A183679 * A183681 A183682 A183683 KEYWORD nonn,tabl AUTHOR R. H. Hardin Jan 06 2011 STATUS approved

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