A224349 Number of n X 4 0..2 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.

15, 225, 2321, 19608, 160362, 1351748, 11704964, 102319662, 895494806, 7833508842, 68530349850, 599768316699, 5250822841015, 45977188883801, 402610713736831, 3525653178203557, 30874547729660838, 270374890703092436

Offset

1,1

Comments

Column 4 of A224353.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -58*a(n-2) -13*a(n-3) +543*a(n-4) -1609*a(n-5) +1864*a(n-6) -17378*a(n-7) +62814*a(n-8) +73709*a(n-9) -307108*a(n-10) +721338*a(n-11) -862742*a(n-12) +4668915*a(n-13) -12478479*a(n-14) -3206649*a(n-15) +1858428*a(n-16) +5104796*a(n-17) +28929803*a(n-18) +21290844*a(n-19) +12857067*a(n-20) -28005842*a(n-21) -37205324*a(n-22) -26318800*a(n-23) -9161072*a(n-24) -1481856*a(n-25) -6336*a(n-26).

Example

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

Crossrefs

Cf. A224353.

Sequence in context: A224264 A223921 A224191 * A224008 A012852 A171289

Adjacent sequences: A224346 A224347 A224348 * A224350 A224351 A224352

Keyword

nonn

Author

R. H. Hardin, Apr 04 2013

Status

approved