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

1,1

Comments

Row 4 of A223789

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

Example

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

Crossrefs

Sequence in context: A178513 A016948 A206993 * A206935 A206870 A181223

Adjacent sequences: A223788 A223789 A223790 * A223792 A223793 A223794

Keyword

nonn

Author

R. H. Hardin Mar 27 2013

Status

approved