A223827 Number of n X 4 0..2 arrays with rows and columns unimodal.

46, 2116, 51136, 738482, 7291180, 54035194, 320423509, 1590193515, 6823643014, 25942390362, 89032405314, 279892497568, 815488308996, 2223043463584, 5714420877205, 13941660959025, 32460302492138, 72461547637300

Offset

1,1

Comments

Column 4 of A223831.

Links

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

Formula

Empirical: a(n) = (456419/5230697472000)*n^16 + (35741/12108096000)*n^15 + (154711/2874009600)*n^14 + (1309129/2075673600)*n^13 + (149137159/28740096000)*n^12 + (924691/29568000)*n^11 + (261112321/1828915200)*n^10 + (17095201/33868800)*n^9 + (7372850867/5225472000)*n^8 + (227410163/72576000)*n^7 + (8054484973/1437004800)*n^6 + (6610049/831600)*n^5 + (112396487393/12108096000)*n^4 + (4125505841/504504000)*n^3 + (671183/110880)*n^2 + (27067/10010)*n + 1.

Example

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

Crossrefs

Cf. A223831.

Sequence in context: A158752 A223738 A223721 * A223785 A264525 A223971

Adjacent sequences: A223824 A223825 A223826 * A223828 A223829 A223830

Keyword

nonn

Author

R. H. Hardin, Mar 27 2013

Status

approved