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%I #6 Feb 28 2013 09:21:05
%S 6,36,936,81936,64181936,3616164181936,93613613616164181936,
%T 819361936193613613616164181936,
%U 641819361819361819361936193613613616164181936
%N a(1)=6; a(n) is concatenation of the squares of each digit of a(n-1), in order (in base 10).
%C If m is a member of the sequence consisting of k base-10 digits, every member of the sequence greater than m is congruent to m modulo 10^k.
%e a(4)=81936 because the squares of the digits of a(3)--namely, 9, 3 and 6--are 81, 9 and 36 respectively.
%t NestList[FromDigits[Flatten[IntegerDigits/@(IntegerDigits[#]^2)]]&,6,10] (* _Harvey P. Dale_, Feb 28 2013 *)
%Y Cf. A061588, A082026.
%K base,easy,nonn
%O 1,1
%A _Matthew Vandermast_, Apr 01 2003