

A241238


Number of acute isosceles triangles, distinct up to congruence, on a centered hexagonal grid of size n.


1



0, 2, 11, 25, 50, 76, 117, 161, 216, 276, 352, 422, 516, 606, 720, 826, 949, 1079, 1222, 1367, 1534
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

A centered hexagonal grid of size n is a grid with A003215(n1) points forming a hexagonal lattice.


LINKS

Eric Weisstein's World of Mathematics, Hex Number.


FORMULA



EXAMPLE

For n = 2 the two kinds of noncongruent acute isosceles triangles are the following:
/. * * .
. * * . . *
\. . * .


CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



