The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A230048 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A230048

Squarefree odious numbers.
(history; published version)

#17 by Joerg Arndt at Fri Mar 15 02:25:43 EDT 2024

STATUS

editing

approved

#16 by Paolo P. Lava at Thu Mar 14 16:29:18 EDT 2024

MAPLE

with(numtheory); P:=proc(q) local n;

for n from 1 to q do if issqrfree(n) then

if type(add(a, a=convert(n, base, 2)), odd) then print(n);

fi; fi; od; end: P(10^3); # Paolo P. Lava, Oct 09 2013

STATUS

approved

editing

#15 by Giovanni Resta at Tue Dec 10 04:00:48 EST 2019

STATUS

reviewed

approved

#14 by Michel Marcus at Tue Dec 10 03:59:50 EST 2019

STATUS

proposed

reviewed

#13 by Amiram Eldar at Tue Dec 10 03:48:48 EST 2019

STATUS

editing

proposed

#12 by Amiram Eldar at Tue Dec 10 03:41:19 EST 2019

LINKS

Amiram Eldar, <a href="/A230048/b230048.txt">Table of n, a(n) for n = 1..10000</a>

FORMULA

Intersection of A000069 and A005117.

MATHEMATICA

odiousQ[n_] := OddQ @ DigitCount[n, 2][[1]]; Select[Range[200], odiousQ[#] && SquareFreeQ[#] &] (* Amiram Eldar, Dec 10 2019 *)

CROSSREFS

Intersection of A000069 and A005117.

STATUS

approved

editing

#11 by Charles R Greathouse IV at Tue Mar 18 01:45:39 EDT 2014

STATUS

editing

approved

#10 by Charles R Greathouse IV at Tue Mar 18 01:45:36 EDT 2014

PROG

(PARI) is(n)=hammingweight(n)%2 && issquarefree(n) \\ Charles R Greathouse IV, Mar 18 2014

STATUS

approved

editing

#9 by Bruno Berselli at Wed Oct 09 05:29:06 EDT 2013

STATUS

proposed

approved

#8 by Paolo P. Lava at Wed Oct 09 04:49:18 EDT 2013

STATUS

editing

proposed