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 A241227 Number of scalene triangles on a centered hexagonal grid of size n. 3
 0, 12, 648, 6084, 30444, 107376, 302916, 732024, 1576728, 3111012, 5724852, 9952620, 16509336, 26321160, 40567872, 60724104, 88605480, 126413772, 176788476, 242874756, 328359624, 437553360 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A centered hexagonal grid of size n is a grid with A003215(n-1) points forming a hexagonal lattice. LINKS Eric Weisstein's World of Mathematics, Hex Number. Eric Weisstein's World of Mathematics, Scalene Triangle. FORMULA a(n) = A241223(n) - A241228(n). CROSSREFS Cf. A190312. Sequence in context: A013587 A126159 A220992 * A268549 A071307 A195574 Adjacent sequences:  A241224 A241225 A241226 * A241228 A241229 A241230 KEYWORD nonn,more AUTHOR Martin Renner, Apr 17 2014 EXTENSIONS a(7) from Martin Renner, May 31 2014 a(8)-a(22) from Giovanni Resta, May 31 2014 STATUS approved

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Last modified July 24 18:34 EDT 2021. Contains 346273 sequences. (Running on oeis4.)