A238810 Number of nX6 0..2 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of the sum of elements above it, modulo 3

7, 58, 498, 4167, 31125, 197418, 1055763, 4880856, 19977948, 73988808, 252222789, 801902972, 2401864834, 6830347670, 18555055873, 48388061335, 121621970223, 295617804194, 696809050142, 1596626133081, 3563675765061, 7762159805512

Offset

1,1

Comments

Column 6 of A238812

Links

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

Formula

Empirical: a(n) = (1/1520925880320000)*n^21 - (521/4001483566080000)*n^20 + (280733/18246765061324800)*n^19 - (1009091/800296713216000)*n^18 + (1263428351/16005934264320000)*n^17 - (87961871/22417274880000)*n^16 + (157308110957/988601822208000)*n^15 - (561404357/105080976000)*n^14 + (32579981539913/217275125760000)*n^13 - (32002299106123/9053130240000)*n^12 + (507775457096141/7242504192000)*n^11 - (201470624506693/172440576000)*n^10 + (24782574974039318761/1520925880320000)*n^9 - (88935042592877896031/470762772480000)*n^8 + (127322197843062321569/70614415872000)*n^7 - (164460777264425293243/11769069312000)*n^6 + (1692671803663313850131/19615115520000)*n^5 - (3282324324299663003969/7939451520000)*n^4 + (598543228210824605143/405242838000)*n^3 - (57018800117252562839/15437822400)*n^2 + (25752092538637987/4476780)*n - 4188294729 for n>8

Example

Some solutions for n=5
..0..0..0..0..2..2....0..0..0..0..2..2....0..2..2..0..0..0....0..0..0..2..2..0
..0..0..0..0..2..2....0..2..2..0..1..1....0..2..1..0..0..2....0..0..0..2..1..2
..0..0..2..2..0..1....0..2..1..0..0..0....0..0..0..0..2..2....0..0..0..0..2..2
..0..0..2..2..0..1....0..0..0..0..0..0....2..1..0..2..1..0....0..2..2..0..1..1
..2..2..1..1..0..2....2..1..0..0..0..0....2..1..0..2..2..1....2..1..2..1..2..1

Crossrefs

Sequence in context: A202975 A051816 A015566 * A362210 A334610 A244469

Adjacent sequences: A238807 A238808 A238809 * A238811 A238812 A238813

Keyword

nonn

Author

R. H. Hardin, Mar 05 2014

Status

approved