This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A358705 #24 Dec 01 2022 17:21:03 %S A358705 345918672,351987624,359841267,394675182,429715863,439516278, %T A358705 487256193,527394816,527498163,528714396,572493816,592681437, %U A358705 729564183,746318529,749258163,754932681,759142683,759823641,762491835,783942561,784196235,845691372,891357624,914863275,915786423,923165487,928163754,976825431 %N A358705 Zeroless pandigital numbers whose square has each digit 1 to 9 twice. %e A358705 345918672 is a term since its square 119659727638243584 contains all digits 1..9 twice each. %p A358705 R:= NULL: %p A358705 for t in combinat:-permute([$1..9]) do %p A358705 x:= add(t[i]*10^(i-1),i=1..9); %p A358705 if sort(convert(x^2,base,10)) = [seq(i$2,i=1..9)] then %p A358705 R:= R, x %p A358705 fi %p A358705 od: %p A358705 sort([R]); # _Robert Israel_, Nov 27 2022 %o A358705 (Python) %o A358705 from itertools import permutations as per %o A358705 a=[] %o A358705 for n in [int(''.join(d)) for d in per('123456789', 9)]: %o A358705 if all(str(n**2).count(d) ==2 for d in '123456789'): %o A358705 a.append(n) %o A358705 print(a) %Y A358705 Cf. A050289, A199630. %K A358705 nonn,base,fini,full %O A358705 1,1 %A A358705 _Zhining Yang_, Nov 27 2022