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!)
A334484 a(n) is the Y-coordinate of the n-th point of the Sierpinski arrowhead curve; sequence A334483 gives X-coordinates. 2
0, 0, 1, 2, 3, 3, 2, 1, 0, 0, 1, 1, 0, 0, 1, 2, 2, 3, 4, 5, 5, 4, 4, 5, 6, 6, 7, 8, 9, 9, 8, 8, 9, 10, 10, 11, 12, 12, 13, 14, 15, 15, 14, 13, 12, 12, 11, 10, 10, 9, 8, 8, 9, 9, 8, 7, 6, 6, 5, 4, 4, 5, 5, 4, 3, 2, 2, 1, 0, 0, 1, 1, 0, 0, 1, 2, 3, 3, 2, 1, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Coordinates are given on a hexagonal lattice with X-axis and Y-axis as follows:

           Y

          /

         /

        0 ---- X

LINKS

Rémy Sigrist, Table of n, a(n) for n = 0..2187

Rémy Sigrist, PARI program for A334484

Wikipedia, Arrowhead curve

Index entries for sequences related to coordinates of 2D curves

FORMULA

A262174(1 + A334483(n) + a(n), 1 + a(n)) = 1 + n for any n >= 0.

EXAMPLE

The Sierpinski arrowhead curve starts (on a hexagonal lattice) as follows:

                         +

                        27\

                           \

                            +

                           /26

                          /

                    +----+

                   /24   25

                  /

                 +          +----+

                23\        /20  19\

                   \      /        \

                    +----+          +

                    22   21        /18

                                  /

            +----+               +

           /4    5\             17\

          /        \               \

         +          +               +----+

         3\        /6               16  15\

           \      /                        \

            +    +          +----+          +

           /2    7\        /10  11\        /14

          /        \      /        \      /

    +----+          +----+          +----+

    0    1          8    9          12   13

- hence a(3) = a(6) = a(15) = a(16) = 2.

PROG

(PARI) See Links section.

CROSSREFS

Cf. A262174, A334483.

Sequence in context: A101914 A099530 A167544 * A334234 A291196 A279316

Adjacent sequences:  A334481 A334482 A334483 * A334485 A334486 A334487

KEYWORD

nonn

AUTHOR

Rémy Sigrist, May 03 2020

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 October 22 21:12 EDT 2021. Contains 348180 sequences. (Running on oeis4.)