A202904 Number of n X 6 0..1 arrays with every one equal to some NW, E or S neighbor.

1, 344, 16062, 538672, 19675348, 734614472, 27173404568, 1004314801728, 37150257828816, 1374167316241760, 50826441572407904, 1879942732569197184, 69534653388866844992, 2571919585157154125440, 95129106434387390980480

Offset

1,2

Links

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

Formula

Empirical: a(n) = 64*a(n-1) -1428*a(n-2) +23104*a(n-3) -359812*a(n-4) +4291328*a(n-5) -41248448*a(n-6) +374113600*a(n-7) -2765377536*a(n-8) +16066440192*a(n-9) -85494580224*a(n-10) +388914239488*a(n-11) -1383466633216*a(n-12) +4562035998720*a(n-13) -14299390476288*a(n-14) +37484061147136*a(n-15) -113414227689472*a(n-16) +433921159331840*a(n-17) -1553250990424064*a(n-18) +5441033254993920*a(n-19) -17912970109779968*a(n-20) +49554669076217856*a(n-21) -116701869358710784*a(n-22) +242127262453858304*a(n-23) -438801431827316736*a(n-24) +692536817349558272*a(n-25) -963631848901050368*a(n-26) +1180232308288913408*a(n-27) -1255235273860579328*a(n-28) +1152998968636997632*a(n-29) -911239313994285056*a(n-30) +609512621590183936*a(n-31) -338901163359338496*a(n-32) +155199364795465728*a(n-33) -55989331109609472*a(n-34) +13458022323978240*a(n-35) -1424967069597696*a(n-36) for n>37.

Example

Some solutions for n=3
..1..1..0..1..1..0....1..1..0..0..1..0....1..1..1..1..1..0....0..1..1..0..1..1
..1..1..1..1..1..1....1..1..0..1..1..1....0..1..0..1..1..0....1..0..1..1..0..1
..0..0..0..0..0..1....0..1..0..0..1..1....0..1..1..0..1..0....1..1..1..1..1..0

Crossrefs

Column 6 of A202906.

Sequence in context: A183673 A231028 A185746 * A086028 A220650 A178191

Adjacent sequences: A202901 A202902 A202903 * A202905 A202906 A202907

Keyword

nonn

Author

R. H. Hardin, Dec 25 2011

Status

approved