A257197 - OEIS

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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.

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Felix Fröhlich, Table of n, a(n) for n = 1..10000

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

CROSSREFS

Cf. A256630, A256631, A256633, A256634, A256708, A256709, A256889, A257210, A257211.

Sequence in context: A327110 A255925 A095623 * A105934 A217256 A179168

Adjacent sequences: A257194 A257195 A257196 * A257198 A257199 A257200

KEYWORD

base,nonn

AUTHOR

Felix Fröhlich, Apr 18 2015

EXTENSIONS

Corrected b-file from Felix Fröhlich, Mar 18 2022

STATUS

approved