%I #12 May 03 2020 13:43:53
%S 1,11,100,111,1000,1010,1100,1111,10000,10010,10100,10110,11000,11010,
%T 11100,11110,11111,31003,99190,100000,100010,100100,100110,101000,
%U 101010,101100,101101,101110,110000,110010,110100,110110,111000,111010,111100,111111,266616
%N Positive numbers k of the form x*y where k, x and y have the same set of decimal digits.
%C If k belongs to the sequence, then 100*k also belongs to the sequence.
%C The positive repunits belong to the sequence.
%C The first pandigital term is 1047463798950190521 = 1023456789^2.
%H Rémy Sigrist, <a href="/A330898/b330898.txt">Table of n, a(n) for n = 1..10000</a>
%e The first terms, alongside an appropriate factorization and the corresponding set of digits, are:
%e n a(n) x y digits(n)
%e -- ------ --- ------ ---------
%e 1 1 1 1 {1}
%e 2 11 1 11 {1}
%e 3 100 10 10 {0, 1}
%e 4 111 1 111 {1}
%e 5 1000 10 100 {0, 1}
%e 6 1010 10 101 {0, 1}
%e 7 1100 10 110 {0, 1}
%e 8 1111 1 1111 {1}
%e 9 10000 10 1000 {0, 1}
%e 10 10010 10 1001 {0, 1}
%e 11 10100 10 1010 {0, 1}
%e 12 10110 10 1011 {0, 1}
%e 13 11000 10 1100 {0, 1}
%e 14 11010 10 1101 {0, 1}
%e 15 11100 10 1110 {0, 1}
%e 16 11110 101 110 {0, 1}
%e 17 11111 1 11111 {1}
%e 18 31003 103 301 {0, 1, 3}
%e 19 99190 109 910 {0, 1, 9}
%o (PARI) is(n) = { my (s=Set(digits(n))); fordiv (n, d, if (Set(digits(d))==s && Set(digits(n/d))==s, return (1))); return (0) }
%Y Cf. A002275, A086066.
%K nonn,base
%O 1,2
%A _Rémy Sigrist_, May 01 2020