A224370 Number of n X 4 0..2 arrays with rows unimodal and antidiagonals nondecreasing.

46, 698, 7608, 77793, 800309, 8297747, 86251004, 896856330, 9325161494, 96954549463, 1008030060622, 10480399768714, 108963825909899, 1132887953497801, 11778544075116434, 122460568078334321

Offset

1,1

Comments

Column 4 of A224374.

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) + 105*a(n-3) + 20*a(n-4) - 183*a(n-5) + 220*a(n-6) + 240*a(n-7) for n>8.

Empirical g.f.: x*(46 + 8*x - 194*x^2 - 673*x^3 + 468*x^4 + 724*x^5 - 90*x^6 - 45*x^7) / (1 - 15*x + 58*x^2 - 105*x^3 - 20*x^4 + 183*x^5 - 220*x^6 - 240*x^7). - Colin Barker, Aug 30 2018

Example

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

Crossrefs

Cf. A224374.

Sequence in context: A223929 A224053 A224306 * A078156 A341428 A066405

Adjacent sequences: A224367 A224368 A224369 * A224371 A224372 A224373

Keyword

nonn

Author

R. H. Hardin, Apr 05 2013

Status

approved