A223986 Number of nX7 0..3 arrays with rows unimodal and columns nondecreasing

1163, 165212, 8350154, 219861244, 3661410444, 43307637038, 392525216516, 2873859236297, 17659521902693, 93729371629362, 439299889862080, 1850116568165210, 7099972695985506, 25111747601307148, 82630828730010090

Offset

1,1

Comments

Column 7 of A223987

Links

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

Formula

Empirical: a(n) = (3642102403/12772735542927360000)*n^21 + (1828819507/93573154160640000)*n^20 + (115124770751/182467650613248000)*n^19 + (8318749/652138905600)*n^18 + (446143076989/2462451425280000)*n^17 + (1206525314927/627683696640000)*n^16 + (31263943588093/1977203644416000)*n^15 + (7783056899227/75322043596800)*n^14 + (3079623865184773/5649153269760000)*n^13 + (32370958783969/13795246080000)*n^12 + (120111458340271/14485008384000)*n^11 + (93158829341993/3862668902400)*n^10 + (2280948080961292511/39544072888320000)*n^9 + (371762262630263/3292047360000)*n^8 + (5068740614675741/28245766348800)*n^7 + (34137353132761/149448499200)*n^6 + (11720474642505173/51301071360000)*n^5 + (539294046816389/3087564480000)*n^4 + (12076668593664427/123193822752000)*n^3 + (2595939553/68468400)*n^2 + (104988181/11639628)*n + 1

Example

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

Crossrefs

Sequence in context: A152307 A224172 A223863 * A224063 A224049 A224280

Adjacent sequences: A223983 A223984 A223985 * A223987 A223988 A223989

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved