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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
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 28 2014
STATUS
approved