1,1

R. H. Hardin, Table of n, a(n) for n = 1..204

Empirical: a(n) = (1/35608838483312640000)*n^24 - (1/989134402314240000)*n^23 + (601/8515157028618240000)*n^22 - (547/425757851430912000)*n^21 + (13921/270322445352960000)*n^20 - (200479/608225502044160000)*n^19 + (115963/6590678814720000)*n^18 + (117617/1244905998336000)*n^17 + (252537361/52725430517760000)*n^16 + (879308299/13181357629440000)*n^15 + (134826737/114124308480000)*n^14 - (85421863/37661021798400)*n^13 + (32134877807171/52725430517760000)*n^12 - (2871377051923/488198430720000)*n^11 + (1288837369490701/13181357629440000)*n^10 - (184837585191797/329533940736000)*n^9 + (23642024191142869/5335311421440000)*n^8 - (12049177715869673/1000370891520000)*n^7 + (510702403798050053/44349776190720000)*n^6 + (72547792289651647/739162936512000)*n^5 - (132132690434377993/149325845760000)*n^4 + (83209134313815637/41064607584000)*n^3 + (10053832694553481/264561897600)*n^2 - (1502154800678423/5354228880)*n + 570714 for n>6.

Some solutions for n=3:

..0..0..0....0..0..0....0..0..0....0..1..1....0..0..0....0..0..0....0..0..0

..0..0..0....0..0..0....0..0..0....0..1..1....0..0..0....1..1..0....0..1..1

..0..0..1....1..2..0....1..0..0....0..2..1....0..1..1....1..1..0....1..1..2

..0..0..1....1..2..2....2..0..0....1..2..2....0..1..1....1..1..0....1..1..2

..0..0..2....2..2..2....2..1..0....2..2..2....1..2..1....2..2..0....1..2..2

..0..2..2....2..2..2....2..1..1....2..2..2....2..2..2....2..2..0....1..2..2

Row 6 of A224262.

Sequence in context: A208043 A208032 A264368 * A223923 A224351 A224193

Adjacent sequences: A224263 A224264 A224265 * A224267 A224268 A224269

R. H. Hardin, Apr 02 2013

Name corrected by Andrew Howroyd, Mar 18 2025

approved