Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #10 Jul 23 2013 03:52:56
%S 990100,999900010000,999999000001000000,999999990000000100000000,
%T 999999999900000000010000000000,999999999999000000000001000000000000,
%U 999999999999990000000000000100000000000000
%N a(n)= A*10^(3*n)+B with A=(10^(3*n)-10^n) and B=10^(2*n).
%e a(2) = (10^6-10^2)*10^6+10^4 = 999900010000.
%e Note that 999900010000 = 999900^2 + 010000^2 (see A055616).
%o (PARI) a(n) = (10^(3*n)-10^n)*10^(3*n) + 10^(2*n) \\ _Michel Marcus_, Jul 23 2013
%Y Subsequence of A055616.
%K nonn,easy
%O 1,1
%A Ulrich Schimke (ulrschimke(AT)aol.com)