A250138 Number of length n+2 0..6 arrays with the medians of every three consecutive terms nondecreasing.

343, 1799, 9156, 46914, 217856, 974944, 4350588, 18667931, 77880418, 322089271, 1307443907, 5208681584, 20546907053, 80150786624, 308819454899, 1179461682136, 4468650085856, 16786704855127, 62609587475559

Offset

1,1

Comments

Column 6 of A250140.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -21*a(n-2) +147*a(n-3) -672*a(n-4) +1526*a(n-5) -7399*a(n-6) +25649*a(n-7) -42973*a(n-8) +192307*a(n-9) -514173*a(n-10) +575399*a(n-11) -3074566*a(n-12) +5772926*a(n-13) -3135200*a(n-14) +33671364*a(n-15) -31736296*a(n-16) -6174074*a(n-17) -268252277*a(n-18) -22436585*a(n-19) +124952727*a(n-20) +1541722905*a(n-21) +1602276594*a(n-22) +140604582*a(n-23) -5840564831*a(n-24) -11203950193*a(n-25) -7301869176*a(n-26) +11531631728*a(n-27) +38571124984*a(n-28) +41463778840*a(n-29) +1826080960*a(n-30) -68505468224*a(n-31) -106915234608*a(n-32) -60747512976*a(n-33) +46128994560*a(n-34) +130831309440*a(n-35) +115397395200*a(n-36) +23935046400*a(n-37) -56194560000*a(n-38) -71456256000*a(n-39) -37324800000*a(n-40) -7464960000*a(n-41).

Example

Some solutions for n=4
..5....2....1....6....2....5....2....4....4....6....2....3....3....0....0....6
..0....1....1....4....5....0....0....0....2....2....0....1....1....6....1....5
..0....0....6....2....4....3....3....2....2....0....6....4....6....2....6....5
..1....4....1....5....4....5....5....2....5....6....5....4....3....2....1....6
..4....6....4....4....2....6....2....2....5....4....3....4....4....4....3....5
..0....5....5....5....4....5....5....3....5....4....5....1....4....2....6....5

Crossrefs

Cf. A250140.

Sequence in context: A075546 A167733 A167730 * A016923 A016983 A267321

Adjacent sequences: A250135 A250136 A250137 * A250139 A250140 A250141

Keyword

nonn

Author

R. H. Hardin, Nov 13 2014

Status

approved