A224055 Number of nX6 0..2 arrays with rows and columns unimodal and antidiagonals nondecreasing

148, 4690, 57911, 428949, 2392915, 11231300, 46853641, 179545949, 646161612, 2215310269, 7295294696, 23173431000, 71137228340, 211216789027, 606907100518, 1688654512840, 4553248388246, 11908977568334, 30245780813181

Offset

1,1

Comments

Column 6 of A224057

Links

R. H. Hardin, Table of n, a(n) for n = 1..178

Formula

Empirical: a(n) = (1/35608838483312640000)*n^24 + (1/593480641388544000)*n^23 + (1/11491439984640000)*n^22 + (59/20274183401472000)*n^21 + (204271/2432902008176640000)*n^20 + (34451/17377871486976000)*n^19 + (18917939/448166159400960000)*n^18 + (769849/995924798668800)*n^17 + (226679623/17575143505920000)*n^16 + (2152013/11412430848000)*n^15 + (706815667/289700167680000)*n^14 + (9710969/517321728000)*n^13 + (22058018740169/52725430517760000)*n^12 + (883262112781/878757175296000)*n^11 + (30292372315283/675967057920000)*n^10 + (425362282393/5977939968000)*n^9 + (18858448588311589/8002967132160000)*n^8 - (2707211596157/114328101888000)*n^7 + (2638894624680309119/59133034920960000)*n^6 - (590269621381831/6636704256000)*n^5 + (21039414018476657/25935541632000)*n^4 - (10575054526365457/1955457504000)*n^3 + (4363361309424841/172982779200)*n^2 + (520015184729/102965940)*n - 216272 for n>7

Example

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

Crossrefs

Sequence in context: A223916 A224188 A223931 * A224308 A224372 A185478

Adjacent sequences: A224052 A224053 A224054 * A224056 A224057 A224058

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved