A224060 Number of nX4 0..3 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.
130, 4580, 58814, 506513, 3509115, 21167501, 114643788, 564290412, 2542634801, 10557558941, 40668731568, 146309729951, 494716846368, 1581405249972, 4804031345110, 13933344725622, 38739584907398, 103620108265460
Offset: 1
Keywords
Examples
Some solutions for n=3 ..1..1..2..2....0..1..0..0....3..2..0..0....1..2..2..1....0..1..1..0 ..1..2..2..2....0..2..3..1....0..3..3..3....1..3..3..3....1..1..1..1 ..2..3..2..2....0..1..3..3....0..3..3..3....1..1..3..3....0..2..2..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/2906843957821440000)*n^24 + (1/80745665495040000)*n^23 + (14503/17841281393295360000)*n^22 + (4577/187146308321280000)*n^21 + (57773/73169985208320000)*n^20 + (451967/24825530695680000)*n^19 + (25829959/64023737057280000)*n^18 + (161591629/21341245685760000)*n^17 + (1317174581/10042939146240000)*n^16 + (1042229807/684745850880000)*n^15 + (224775509633/15064408719360000)*n^14 + (255513067541/1076029194240000)*n^13 - (126037283815777/331416991825920000)*n^12 + (4311994432289/156920924160000)*n^11 - (290647612737067/2510734786560000)*n^10 + (5895362157233/4526565120000)*n^9 - (80296454539927819/32011868528640000)*n^8 + (2890170225407863/285820254720000)*n^7 + (6620255551080740287/152056375511040000)*n^6 - (119874811010411/95995186560000)*n^5 - (594949061071512629/422378820864000)*n^4 + (3927812632523993/279351072000)*n^3 - (77971408834461167/1562307626880)*n^2 + (50159875988069/1784742960)*n + 138193 for n>7
Comments