The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A052081 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A052081

Numbers k such that k^2 is a square whose decimal expansion's digits are grouped together.
(history; published version)

#17 by OEIS Server at Wed Nov 08 14:27:42 EST 2023

LINKS

Robert Israel, <a href="/A052081/b052081_1.txt">Table of n, a(n) for n = 1..10000</a>

#16 by Peter Luschny at Wed Nov 08 14:27:42 EST 2023

STATUS

reviewed

approved

Discussion

Wed Nov 08

14:27

OEIS Server: Installed first b-file as b052081.txt.

#15 by Stefano Spezia at Wed Nov 08 13:53:59 EST 2023

STATUS

proposed

reviewed

#14 by Robert Israel at Wed Nov 08 12:54:05 EST 2023

STATUS

editing

proposed

#13 by Robert Israel at Wed Nov 08 12:53:58 EST 2023

LINKS

Robert Israel, <a href="/A052081/b052081_1.txt">Table of n, a(n) for n = 1..10000</a>

MAPLE

filter:= proc(n) local L, i, v, V;

L:= convert(n^2, base, 10);

for i from 1 to nops(L) do

v:= L[i];

if not assigned(V[v]) then V[v]:= i

elif V[v] < i-1 then return false

else V[v]:= i

fi

od;

true

end proc:

select(filter, [$0..100]); # Robert Israel, Nov 08 2023

STATUS

approved

editing

#12 by Joerg Arndt at Fri Jun 18 02:45:26 EDT 2021

STATUS

reviewed

approved

#11 by Jon E. Schoenfield at Thu Jun 17 18:03:33 EDT 2021

STATUS

proposed

reviewed

#10 by Wesley Ivan Hurt at Thu Jun 17 17:50:42 EDT 2021

STATUS

editing

proposed

#9 by Wesley Ivan Hurt at Thu Jun 17 17:50:10 EDT 2021

NAME

Numbers k with the property such that k^2 is a square whose decimal expansion's digits are grouped together.

EXAMPLE

81 is not a term since in 81^2 = 6561 , the two digits 6 's are separated by the 5.

88 is a term since in 88^2 = 7744 , the digits 7 and 4 are grouped.

STATUS

approved

editing

#8 by Sean A. Irvine at Thu Oct 17 22:40:01 EDT 2019

STATUS

proposed

approved