A241227 Number of scalene triangles on a centered hexagonal grid of size n.

0, 12, 648, 6084, 30444, 107376, 302916, 732024, 1576728, 3111012, 5724852, 9952620, 16509336, 26321160, 40567872, 60724104, 88605480, 126413772, 176788476, 242874756, 328359624, 437553360

Offset: 1

Author

Martin Renner, Apr 17 2014

Keywords

• nonn
• more

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.

Crossrefs

Cf. A190312.

Formula

a(n) = A241223(n) - A241228(n).

Extensions

a(7) from Martin Renner, May 31 2014

a(8)-a(22) from Giovanni Resta, May 31 2014