A239845 Number of nX3 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4

4, 17, 68, 244, 777, 2221, 5853, 14488, 34057, 76495, 164823, 341898, 685019, 1329596, 2506729, 4601633, 8242778, 14435568, 24759659, 41655972, 68838529, 111877953, 179018454, 282309115, 439154169, 674416741, 1023247403, 1534854222

Offset

1,1

Comments

Column 3 of A239849

Links

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

Formula

Empirical: a(n) = (1/6227020800)*n^13 - (1/119750400)*n^12 + (221/479001600)*n^11 - (103/10886400)*n^10 + (649/4838400)*n^9 + (3569/3628800)*n^8 - (2313347/43545600)*n^7 + (10192331/10886400)*n^6 - (87698557/10886400)*n^5 + (82688371/2721600)*n^4 + (101725069/1247400)*n^3 - (505121941/415800)*n^2 + (698568509/180180)*n - 2851 for n>9

Example

Some solutions for n=4
..0..0..3....0..3..3....0..3..3....0..3..3....0..3..3....0..0..3....0..3..3
..0..3..3....0..3..3....0..3..3....3..1..3....0..3..2....0..0..3....3..1..2
..3..1..2....3..1..0....0..0..0....3..3..0....0..0..3....0..3..1....3..2..0
..3..2..0....3..2..0....3..1..0....0..2..1....0..0..3....3..3..2....0..0..0

Crossrefs

Sequence in context: A244616 A030529 A266862 * A081113 A368429 A114587

Adjacent sequences: A239842 A239843 A239844 * A239846 A239847 A239848

Keyword

nonn

Author

R. H. Hardin, Mar 28 2014

Status

approved