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 A195279 Number of lower triangles of a 3 X 3 integer array with each element differing from all of its vertical and horizontal neighbors by n or less and triangles differing by a constant counted only once. 2
 171, 2125, 11319, 39609, 107811, 248261, 507375, 948209, 1653019, 2725821, 4294951, 6515625, 9572499, 13682229, 19096031, 26102241, 35028875, 46246189, 60169239, 77260441, 98032131, 123049125, 152931279, 188356049, 230061051 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row 3 of A195278. LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 FORMULA Empirical: a(n) = (64/3)*n^5 + (160/3)*n^4 + 56*n^3 + (92/3)*n^2 + (26/3)*n + 1. Conjectures from Colin Barker, Mar 01 2018: (Start) G.f.: x*(171 + 1099*x + 1134*x^2 + 150*x^3 + 7*x^4 - x^5) / (1 - x)^6. a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6. (End) EXAMPLE Some solutions for n=5: ...0.........0.........0.........0.........0.........0.........0.........0 ..-2.-1......3..4.....-3..1.....-4.-1.....-1..4.....-5.-1......5..8......4..4 ..-3.-6.-6...2..1..1..-7.-3..0..-5.-4.-6..-4.-1..3..-7.-2..2...8..5..2...0..0.-2 CROSSREFS Cf. A195278. Sequence in context: A251223 A186868 A185611 * A016058 A332418 A152926 Adjacent sequences:  A195276 A195277 A195278 * A195280 A195281 A195282 KEYWORD nonn AUTHOR R. H. Hardin, Sep 14 2011 STATUS approved

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Last modified July 3 10:25 EDT 2022. Contains 355050 sequences. (Running on oeis4.)