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A181319
Numbers n with property that there is a different number m such that the lunar squares n*n and m*m are the same.
4
11011, 11012, 11013, 11014, 11015, 11016, 11017, 11018, 11019, 11021, 11022, 11023, 11024, 11025, 11026, 11027, 11028, 11029, 11031, 11032, 11033, 11034, 11035, 11036, 11037, 11038, 11039, 11041, 11042, 11043, 11044, 11045, 11046, 11047, 11048, 11049, 11051, 11052, 11053, 11054, 11055, 11056, 11057, 11058
OFFSET
1,1
LINKS
David Applegate and N. J. A. Sloane, Table of n, a(n) for n = 1..21894
D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]
EXAMPLE
11011*11011 = 11111*11111 = 111111111, so 11011 and 11111 are members.
PROG
(ksh script from David Applegate; assumes the dismal C program dismal2a has been installed)
i=0
while [ $i -lt 100000 ]; do
echo $i $(dismal2a -d mul $i $i)
i=$(($i+1))
done | awk '{
nrt[$2]++;
rt[$2]=rt[$2] " " $1;
}
END{
for (i in rt)
if (nrt[i] > 1)
print i, rt[i];
}' | sort -k1, 1n > dismal_multsquares.txt
CROSSREFS
Sequence in context: A267038 A267293 A300557 * A267811 A267934 A218598
KEYWORD
nonn,base
AUTHOR
STATUS
approved