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A240456
Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4
1
4, 21, 102, 476, 2200, 10123, 46471, 213000, 975380, 4464474, 20429739, 93474260, 427645941, 1956395954, 8949898045, 40942368765, 187294120155, 856787747966, 3919414321141, 17929510264717, 82019155503670, 375199231601451
OFFSET
1,1
COMMENTS
Column 2 of A240460
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) -20*a(n-2) +34*a(n-3) -84*a(n-4) +92*a(n-5) -68*a(n-6) +222*a(n-7) +13*a(n-8) -251*a(n-9) +25*a(n-10) -495*a(n-11) +485*a(n-12) -44*a(n-13) -180*a(n-14) +554*a(n-15) -648*a(n-16) +14*a(n-17) +152*a(n-18) -190*a(n-19) -140*a(n-20) +397*a(n-21) -273*a(n-22) +75*a(n-23) +167*a(n-24) -136*a(n-25) +27*a(n-26)
EXAMPLE
Some solutions for n=4
..2..0....2..0....0..2....2..2....0..0....2..2....2..2....2..0....0..2....2..2
..0..2....0..0....2..0....2..2....2..2....0..0....2..2....3..2....2..2....3..2
..3..3....0..0....3..2....2..0....3..2....2..2....0..2....2..2....2..0....3..2
..3..1....2..2....3..1....2..2....3..2....0..2....0..3....0..0....2..0....2..2
CROSSREFS
Sequence in context: A292308 A076901 A080043 * A113022 A291184 A014986
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 05 2014
STATUS
approved