A223791 Number of 4Xn 0..2 arrays with rows, diagonals and antidiagonals unimodal.

81, 6561, 151580, 1560013, 11012718, 61333566, 288823579, 1196519547, 4468789562, 15293854291, 48524120300, 143996244303, 402491787780, 1065874328092, 2687501352957, 6479586585575, 14994608609716, 33416226803133

Offset: 1

Author

R. H. Hardin Mar 27 2013

Keywords

• nonn

Comments

Row 4 of A223789

Examples

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

Links

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

Formula

Empirical: a(n) = (456419/5230697472000)*n^16 + (165527/653837184000)*n^15 + (1160527/37362124800)*n^14 + (4098907/18681062400)*n^13 - (2323961/28740096000)*n^12 + (686821469/7185024000)*n^11 - (1282316951/1828915200)*n^10 + (6465409549/914457600)*n^9 + (69811138547/5225472000)*n^8 - (199799815457/326592000)*n^7 + (10755338490607/1437004800)*n^6 - (18136370082679/359251200)*n^5 + (23466839810116957/108972864000)*n^4 - (2416825957955693/4540536000)*n^3 + (2240986165151/4324320)*n^2 + (7139372965/18018)*n - 659081 for n>8