A250135 Number of length n+2 0..3 arrays with the medians of every three consecutive terms nondecreasing

64, 204, 632, 1959, 5696, 16104, 45232, 124249, 335328, 897523, 2377452, 6233295, 16229424, 41987965, 107948004, 276101588, 703049528, 1782693579, 4503485124, 11339512465, 28466148864, 71263715430, 177963467480, 443410709998

Offset

1,1

Comments

Column 3 of A250140

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -6*a(n-2) +24*a(n-3) -57*a(n-4) +52*a(n-5) -170*a(n-6) +256*a(n-7) -98*a(n-8) +560*a(n-9) -340*a(n-10) -80*a(n-11) -977*a(n-12) -372*a(n-13) +48*a(n-14) +624*a(n-15) +788*a(n-16) +192*a(n-17) -96*a(n-18) -288*a(n-19) -144*a(n-20)

Example

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

Crossrefs

Sequence in context: A220763 A030028 A320338 * A273321 A091077 A245991

Adjacent sequences: A250132 A250133 A250134 * A250136 A250137 A250138

Keyword

nonn

Author

R. H. Hardin, Nov 13 2014

Status

approved