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 A229426 Number of nX6 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing 2
 23, 175, 1116, 5700, 24126, 87648, 281016, 812352, 2152643, 5297329, 12231874, 26724490, 55625600, 110928984, 212948248, 395089316, 710860767, 1243965435, 2122565928, 3539121568, 5777563514, 9250018192, 14545817232, 22496156480 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 6 of A229428 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = (1/11404800)*n^12 + (1/211200)*n^11 + (37/345600)*n^10 + (143/103680)*n^9 + (27977/2419200)*n^8 + (83399/1209600)*n^7 + (321133/1036800)*n^6 + (35291/34560)*n^5 + (66941/28800)*n^4 + (614843/129600)*n^3 + (149511/30800)*n^2 + (19627/3465)*n + 4 EXAMPLE Some solutions for n=4 ..2..2..1..0..0..0....1..0..0..0..0..0....2..2..1..1..1..0....2..2..2..1..1..1 ..2..2..1..1..1..0....2..1..0..0..0..0....2..2..1..1..1..0....2..2..2..1..1..1 ..2..2..1..1..1..0....2..1..0..0..0..0....2..2..2..1..1..0....2..2..2..1..1..1 ..2..2..2..1..1..0....2..2..1..1..0..0....2..2..2..1..1..0....2..2..2..2..1..1 CROSSREFS Sequence in context: A155842 A248698 A186260 * A274587 A302200 A269072 Adjacent sequences:  A229423 A229424 A229425 * A229427 A229428 A229429 KEYWORD nonn AUTHOR R. H. Hardin Sep 22 2013 STATUS approved

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Last modified December 7 05:14 EST 2019. Contains 329839 sequences. (Running on oeis4.)