The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A348911 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A348911

a(n) is the "w" part of f(n) = Sum_{k>=0, d_k>0} w^(d_k-1) * (-2)^k where Sum_{k>=0} d_k * 4^k is the base-4 representation of n and w = -1/2 + sqrt(-3)/2 is a primitive cube root of unity; sequence A348910 gives "real" parts.
(history; published version)

#14 by N. J. A. Sloane at Tue Nov 09 15:01:46 EST 2021

STATUS

reviewed

approved

#13 by Michel Marcus at Tue Nov 09 14:43:14 EST 2021

STATUS

proposed

reviewed

#12 by Rémy Sigrist at Tue Nov 09 12:45:10 EST 2021

STATUS

editing

proposed

#11 by Rémy Sigrist at Tue Nov 09 12:39:42 EST 2021

LINKS

Rémy Sigrist, <a href="/A348911/b348911.txt">Table of n, a(n) for n = 0..16383</a>

STATUS

approved

editing

Discussion

Tue Nov 09

12:45

Rémy Sigrist: added b-file

#10 by N. J. A. Sloane at Tue Nov 09 05:37:29 EST 2021

STATUS

proposed

approved

#9 by Rémy Sigrist at Mon Nov 08 14:31:00 EST 2021

STATUS

editing

proposed

#8 by Rémy Sigrist at Mon Nov 08 11:38:41 EST 2021

COMMENTS

It appears that The function f defines a bijection from the nonnegative integers to the Eisenstein integers.

STATUS

proposed

editing

#7 by Rémy Sigrist at Sat Nov 06 09:39:47 EDT 2021

STATUS

editing

proposed

#6 by Rémy Sigrist at Thu Nov 04 12:55:31 EDT 2021

LINKS

Gary Teachout, <a href="http://teachout1.net/village/fill2.html">Fractal Space Filling Curves 2002</a>

#5 by Rémy Sigrist at Wed Nov 03 16:16:53 EDT 2021

LINKS

Wikipedia, <a href="https://en.wikipedia.org/wiki/Eisenstein_integer">Eisenstein integer</a>

FORMULA

a(2^(k+1)) = A077966(k) for any k >= 0.

CROSSREFS

Cf. A077966, A348910.