A223867 Number of 4Xn 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.
35, 1225, 24199, 315124, 3017129, 22852913, 144081276, 784071455, 3781718633, 16487698435, 65952999251, 244841613810, 851144356707, 2790551617469, 8678912669190, 25728520577688, 72995578880032, 198891717017532
Offset: 1
Keywords
Examples
Some solutions for n=3 ..2..1..1....3..3..0....0..0..2....0..2..1....0..2..0....1..1..0....0..0..0 ..2..3..1....3..3..1....0..3..2....2..3..1....1..2..0....2..1..0....0..1..0 ..2..3..1....3..3..1....0..3..2....2..3..1....2..3..0....2..2..1....0..3..3 ..2..3..2....3..3..3....1..3..3....3..3..3....3..3..3....2..3..2....0..3..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/2906843957821440000)*n^24 + (1/34605285212160000)*n^23 + (2197/1372406261022720000)*n^22 + (37133/608225502044160000)*n^21 + (45197/25276903981056000)*n^20 + (14623277/347557429739520000)*n^19 + (26489599/32011868528640000)*n^18 + (37041601/2667655710720000)*n^17 + (14981899/74392141824000)*n^16 + (19115865583/7532204359680000)*n^15 + (31834111187/1158800670720000)*n^14 + (66986419663/269007298560000)*n^13 + (122476645127999/66283398365184000)*n^12 + (27904576042121/2510734786560000)*n^11 + (949107163427/17557585920000)*n^10 + (100270802691019/470762772480000)*n^9 + (174267558093661/256094948229120)*n^8 + (2011492987640933/1143281018880000)*n^7 + (61760354830949111/16895152834560000)*n^6 + (4216963085471057/703964701440000)*n^5 + (5310598072571189/703964701440000)*n^4 + (2777655817513/391091500800)*n^3 + (19272574007557/3805621142400)*n^2 + (2059892117/1070845776)*n + 1
Comments