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A257197
Numbers k such that the decimal expansions of both k and k^2 have 1 as smallest digit and 6 as largest digit.
16
116, 146, 1116, 1146, 1156, 1246, 1465, 1556, 1616, 3516, 3621, 4611, 4621, 4631, 11116, 11146, 11156, 11465, 11556, 11642, 15216, 16231, 21556, 22631, 25146, 25162, 25621, 33516, 34156, 35116, 35146, 35162, 36211, 36215, 36512, 46111, 46112, 46211, 46331
OFFSET
1,1
LINKS
MATHEMATICA
sd1Q[n_]:=Module[{idn=IntegerDigits[n]}, Min[idn]==1&&Max[idn]==6]; Select[ Range[50000], AllTrue[{#, #^2}, sd1Q]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 22 2020 *)
PROG
(PARI) is(n) = vecmin(digits(n))==1 && vecmin(digits(n^2))==1 && vecmax(digits(n))==6 && vecmax(digits(n^2))==6
KEYWORD
base,nonn
AUTHOR
Felix Fröhlich, Apr 18 2015
EXTENSIONS
Corrected b-file from Felix Fröhlich, Mar 18 2022
STATUS
approved