The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A281898

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A281898

Numbers n such that n - floor(sqrt(n))^2 and 2n - floor(sqrt(2n))^2 are both squares.
(history; published version)

#29 by Harvey P. Dale at Sat Apr 25 14:49:48 EDT 2020

STATUS

editing

approved

#28 by Harvey P. Dale at Sat Apr 25 14:49:44 EDT 2020

MATHEMATICA

Select[Range[0, 1000], AllTrue[{Sqrt[#-Floor[Sqrt[#]]^2], Sqrt[2#-Floor[ Sqrt[ 2#]]^2]}, IntegerQ]&] (* _The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Apr 25 2020 *)

STATUS

approved

editing

#27 by Harvey P. Dale at Sat Apr 25 14:49:23 EDT 2020

STATUS

editing

approved

#26 by Harvey P. Dale at Sat Apr 25 14:49:20 EDT 2020

MATHEMATICA

Select[Range[0, 1000], AllTrue[{Sqrt[#-Floor[Sqrt[#]]^2], Sqrt[2#-Floor[ Sqrt[ 2#]]^2]}, IntegerQ]&] (* Harvey P. Dale, Apr 25 2020 *)

STATUS

approved

editing

#25 by Joerg Arndt at Fri Feb 10 02:15:58 EST 2017

STATUS

reviewed

approved

#24 by Michel Marcus at Fri Feb 10 00:29:01 EST 2017

STATUS

proposed

reviewed

#23 by Thomas Ordowski at Sat Feb 04 07:04:10 EST 2017

STATUS

editing

proposed

#22 by Thomas Ordowski at Sat Feb 04 06:58:14 EST 2017

CROSSREFS

Cf. A000129, A076218 is a subsequence, A145016.

#21 by Thomas Ordowski at Sat Feb 04 06:44:25 EST 2017

COMMENTS

Also A000129(2k+1)^2 is a subsequence.

CROSSREFS

Cf. A076218, is a subsequence, A145016.

STATUS

proposed

editing

#20 by Michael De Vlieger at Thu Feb 02 20:36:38 EST 2017

STATUS

editing

proposed