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A057659 Prime numbers whose square is composed of just two different decimal digits. 0

%I

%S 5,7,11,109,173,81619

%N Prime numbers whose square is composed of just two different decimal digits.

%C Conjectured to be a finite sequence.

%C No further terms up to Prime[1000000]=15485863 [From Harvey P. Dale, Mar 20 2011]

%D Related to the Unsolved problem F24, p. 262, of the UPiNT by _R. K. Guy_

%e Example: 81619^2 = 6661661161

%t Select[Prime[Range[10000]],Count[DigitCount[#^2],0] ==8&] (* _Harvey P. Dale_, Mar 20 2011 *)

%K easy,nonn,base

%O 0,1

%A _Carlos Rivera_, Oct 15 2000

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Last modified September 22 07:48 EDT 2021. Contains 347605 sequences. (Running on oeis4.)