A137051 - OEIS

%I #14 Apr 21 2024 14:29:21

%S 1,9,141,441,941,1191,99559,118988,445488,999559,9958988,44544191,

%T 445919891,941195441,994458891,9195411891,9459859859,9994941191,

%U 11898949191,44551594191,44555449891,94858548141,99498181488,445145914891,445584958891,919184195441,945944814191,9189418814859,9195188958988,9444544454559

%N Numbers k such that k and k^2 use only the digits 1, 4, 5, 8 and 9.

%C Generated with DrScheme.

%C Conjecture: The only squares present in the sequence are 1, 9, and 441. - _Stefano Spezia_, Apr 18 2024

%H Jonathan Wellons, <a href="/A137051/b137051.txt">Table of n, a(n) for n = 1..49</a>

%H Jonathan Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]

%e 95819859194191^2 = 9181445415994589515848144481.

%t Select[Range[10^6],SubsetQ[{1,4,5,8,9},Union[IntegerDigits[#],IntegerDigits[#^2]]]&] (* _Stefano Spezia_, Apr 18 2024 *)

%K base,nonn

%O 1,2

%A Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008