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

Author

R. H. Hardin, Apr 04 2013

Keywords

• nonn

Comments

Column 4 of A224353.

Examples

			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
		

Links

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

Crossrefs

Cf. A224353.

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) [phone]*a(n-18) [phone]*a(n-19) [phone]*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).