The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A043687 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A043687

a(n) = (s(n)-1)/2, where s(n) is the n-th number whose base-2 representation has exactly 3 runs.
(history; published version)

#14 by Wesley Ivan Hurt at Tue Apr 13 23:08:57 EDT 2021

STATUS

editing

approved

#13 by Wesley Ivan Hurt at Tue Apr 13 23:08:48 EDT 2021

CROSSREFS

Cf. A238246.

STATUS

proposed

editing

#12 by Jon E. Schoenfield at Tue Apr 13 23:07:59 EDT 2021

STATUS

editing

proposed

#11 by Jon E. Schoenfield at Tue Apr 13 23:07:57 EDT 2021

NAME

a(n) = (s(n)-1)/2, where s(n) = is the n-th number whose base -2 representation has exactly 3 runs.

STATUS

approved

editing

#10 by Michel Marcus at Sat Feb 22 05:35:52 EST 2014

STATUS

reviewed

approved

#9 by Joerg Arndt at Sat Feb 22 05:03:57 EST 2014

STATUS

proposed

reviewed

#8 by Vincenzo Librandi at Sat Feb 22 04:31:13 EST 2014

STATUS

editing

proposed

#7 by Vincenzo Librandi at Sat Feb 22 04:31:04 EST 2014

LINKS

Vincenzo Librandi, <a href="/A043687/b043687.txt">Table of n, a(n) for n = 1..1000</a>

MATHEMATICA

(# - 1)/2&/@Select[Range[1000], Length[Split[IntegerDigits[#, 2]]]==3&] (* Vincenzo Librandi, Feb 22 2014 *)

STATUS

approved

editing

#6 by Reinhard Zumkeller at Thu Feb 20 15:37:05 EST 2014

STATUS

editing

approved

#5 by Reinhard Zumkeller at Thu Feb 20 15:13:57 EST 2014

COMMENTS

a(n) = A238246(n) - 1. - Reinhard Zumkeller, Feb 20 2014

STATUS

approved

editing