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A241236 Number of scalene triangles, distinct up to congruence, on a centered hexagonal grid of size n. 2
0, 1, 19, 99, 310, 760, 1556, 2863, 4849, 7713, 11702, 17077, 24066 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

A centered hexagonal grid of size n is a grid with A003215(n-1) points forming a hexagonal lattice.

LINKS

Table of n, a(n) for n=1..13.

Eric Weisstein's World of Mathematics, Hex Number.

Eric Weisstein's World of Mathematics, Scalene Triangle.

FORMULA

a(n) = A241231(n) - A241237(n).

EXAMPLE

For n = 2 the only kind of non-congruent scalene triangles is the following:

/. *

* . *

\. .

CROSSREFS

Cf. A190313, A241227.

Sequence in context: A086120 A129701 A221746 * A044270 A044651 A287303

Adjacent sequences:  A241233 A241234 A241235 * A241237 A241238 A241239

KEYWORD

nonn

AUTHOR

Martin Renner, Apr 17 2014

EXTENSIONS

a(7) from Martin Renner, May 31 2014

a(8)-a(13) from Giovanni Resta, May 31 2014

STATUS

approved

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Last modified June 2 18:25 EDT 2020. Contains 334787 sequences. (Running on oeis4.)