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%I #13 Sep 24 2014 14:11:12
%S 9,624,19040,30222192,592704000,12040481088,128024064000,
%T 1024192512000,3456649728000
%N The first n-fold intrinsically 4-palindromic number (represented in base ten).
%C The fifth and sixth terms are both cubes, exploiting the simple binomial expansion as (m)(m)^3=(m^3)(3m^3)(3m^3)(m^3) for much of their status. - _James G. Merickel_, Dec 19 2009
%C The first base in which the fifth term is 4-palindromic is 209. - _James G. Merickel_, Dec 18 2009
%C a(10) <= 27653197824000, a(11) <= 27653197824000, a(12) <= 575100098496000, a(13) <= 1733189185728000, a(14) <= 1733189185728000, a(15) <= 8400090327552000. - _Hiroaki Yamanouchi_, Sep 24 2014
%e a(2)=624 is 4444 in base 5 and 1551 in base 7.
%Y Cf. A171701, A171702, A171704, A171705, A171706, A171740, A171741, A171742.
%K nonn,base
%O 1,1
%A _James G. Merickel_, Dec 16 2009
%E a(5)-a(6) from _James G. Merickel_, Dec 19 2009
%E a(7)-a(9) from _Hiroaki Yamanouchi_, Sep 24 2014
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