login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A307017 List coordinates (x,y) of the points in an hexagonal grid, sorted first by radial coordinate r and in case of ties, by polar angle 0 <= phi < 2*Pi in a polar coordinate system. Sequence gives the third coordinate in a barycentric coordinate system. 6
0, 1, 1, 0, -1, -1, 0, 2, 1, -1, -2, -1, 1, 2, 2, 0, -2, -2, 0, 3, 3, 2, 1, -1, -2, -3, -3, -2, -1, 1, 2, 3, 3, 0, -3, -3, 0, 4, 2, -2, -4, -2, 2, 4, 4, 3, 1, -1, -3, -4, -4, -3, -1, 1, 3, 4, 4, 0, -4, -4, 0, 5, 5, 3, 2, -2, -3, -5, -5, -3, -2, 2, 3, 5, 5, 4, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

Cartesian coordinates (x,y) of the grid points are converted to barycentric coordinates (i,j,k) by i = x - y/sqrt(3), j = 2*y/sqrt(3), k = x + y/sqrt(3). The sequence gives k. i is given in A307014, j is given in A307016.

LINKS

Hugo Pfoertner, Table of n, a(n) for n = 0..9060, covering range r <= 50.

CROSSREFS

Cf. A004016, A035019, A038590, A307014, A307016.

Sequence in context: A296072 A326700 A050412 * A220424 A182907 A334745

Adjacent sequences:  A307014 A307015 A307016 * A307018 A307019 A307020

KEYWORD

sign,look

AUTHOR

Hugo Pfoertner, Mar 21 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 17 04:55 EDT 2021. Contains 345080 sequences. (Running on oeis4.)