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Numbers in base 10 that are palindromic in bases 3, 7, and 9.
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%I #13 Mar 20 2020 20:15:41

%S 0,1,2,4,8,40,100,164,328,400,8200,14762,532900

%N Numbers in base 10 that are palindromic in bases 3, 7, and 9.

%C Intersection of A014190, A029954, and A029955.

%C No other terms < 10^17. It is likely that there are no more terms. - _Chai Wah Wu_, Mar 20 2020

%e 400 = 112211_3 = 1111_7 = 484_9.

%o (Sage)

%o [n for n in (0..100000) if Word(n.digits(3)).is_palindrome() and Word(n.digits(7)).is_palindrome() and Word(n.digits(9)).is_palindrome()]

%Y Cf. A014190 (base 3), A029954 (base 7), and A029955 (base 9).

%K nonn,base,more

%O 1,3

%A _Jeremias M. Gomes_, Sep 23 2018