A241223 Number of triangles on a centered hexagonal grid of size n.
0, 32, 900, 7380, 34676, 118044, 325872, 775856, 1653888, 3237984, 5923028, 10249596, 16938588, 26924036, 41393424, 61830480, 90059672, 128293728, 179185500, 245889068, 332107188, 442162836, 581060024, 754545360, 969196896, 1232477192, 1552824900
Offset: 1
Keywords
Examples
For n = 2 the 32 triangles are the following: /. * * * * . . . . . . . . * * * . * * . * . * * . * * . . * . . * * * . * . . . \. . . . . . * . * * . * . . * . - /* . . . . * * . . * * * * . . * * . . * . * . . . . . * . . * . . . * . * * . . \. * * . * * . * * . . * . . * . - /* . . . * * * * * . . . . . . * . . . * . * . . * * . . * . . * . . . . * . . * \* * . * . . . . * . * * * * . * - /* . . * * . . . . . . * * . . * . * * * * . . * . * * . . * * . * . . . * * . . \. . . . * . . * * . . * * . . *
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..200
- Eric Weisstein's World of Mathematics, Hex Number.
- Eric Weisstein's World of Mathematics, Triangle.
Crossrefs
Cf. A045996.
Formula
Extensions
a(7) from Martin Renner, May 31 2014
a(8)-a(22) from Giovanni Resta, May 31 2014
Terms a(23) and beyond from Andrew Howroyd, Sep 18 2017
Comments