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A201490 Number of nX2 zero-sum -2..2 arrays with rows and columns lexicographically nondecreasing 1
3, 29, 226, 1454, 7815, 36487, 151593, 571539, 1982705, 6399842, 19389074, 55531190, 151238480, 393631919, 983211316, 2365399764, 5498241469, 12382111994, 27080912704, 57644263473, 119645822176, 242563511707 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A201496
LINKS
FORMULA
Empirical: a(n) = 6*a(n-2) +7*a(n-3) -10*a(n-4) -38*a(n-5) -31*a(n-6) +48*a(n-7) +148*a(n-8) +133*a(n-9) -96*a(n-10) -416*a(n-11) -479*a(n-12) -12*a(n-13) +797*a(n-14) +1265*a(n-15) +706*a(n-16) -835*a(n-17) -2315*a(n-18) -2338*a(n-19) -344*a(n-20) +2577*a(n-21) +4244*a(n-22) +3040*a(n-23) -620*a(n-24) -4336*a(n-25) -5478*a(n-26) -3214*a(n-27) +932*a(n-28) +4370*a(n-29) +5360*a(n-30) +3926*a(n-31) +1155*a(n-32) -1908*a(n-33) -4647*a(n-34) -6321*a(n-35) -5666*a(n-36) -1759*a(n-37) +4482*a(n-38) +9788*a(n-39) +10241*a(n-40) +4382*a(n-41) -4896*a(n-42) -11847*a(n-43) -11847*a(n-44) -4896*a(n-45) +4382*a(n-46) +10241*a(n-47) +9788*a(n-48) +4482*a(n-49) -1759*a(n-50) -5666*a(n-51) -6321*a(n-52) -4647*a(n-53) -1908*a(n-54) +1155*a(n-55) +3926*a(n-56) +5360*a(n-57) +4370*a(n-58) +932*a(n-59) -3214*a(n-60) -5478*a(n-61) -4336*a(n-62) -620*a(n-63) +3040*a(n-64) +4244*a(n-65) +2577*a(n-66) -344*a(n-67) -2338*a(n-68) -2315*a(n-69) -835*a(n-70) +706*a(n-71) +1265*a(n-72) +797*a(n-73) -12*a(n-74) -479*a(n-75) -416*a(n-76) -96*a(n-77) +133*a(n-78) +148*a(n-79) +48*a(n-80) -31*a(n-81) -38*a(n-82) -10*a(n-83) +7*a(n-84) +6*a(n-85) -a(n-87)
EXAMPLE
Some solutions for n=6
.-2..1...-2.-2...-2.-2...-2..1...-2.-2...-1..0...-2.-2...-2..0...-2.-1...-2..2
.-1..2...-1..0...-1..1...-2..2...-1..1....0.-1...-2..1....0.-2...-2..1...-1.-1
..0.-1...-1..1....0.-2...-1.-1....0..2....0.-1...-2..2....0..0....1.-2....0..1
..0..0....1..0....0..0....1.-1....1.-2....1..1....1..0....0..0....1..1....1.-2
..1.-2....1..0....2..0....1.-1....1..0....2.-2....2.-1....1..2....1..1....1..0
..1..1....2..1....2..2....2..1....2..0....2.-1....2..1....2.-1....2.-1....1..0
CROSSREFS
Sequence in context: A174419 A220548 A153825 * A354402 A135163 A074366
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 02 2011
STATUS
approved

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Last modified June 16 19:52 EDT 2024. Contains 373432 sequences. (Running on oeis4.)