%I #3 Mar 30 2012 18:59:02
%S 1,11,111,1011,10111,111011,1100111,10001011,100010111,1100111011,
%T 11101100111,101110001011,1011000010111,11100000111011,
%U 110000001100111,1000000010001011,10000000100010111,110000001100111011
%N A modular binomial transform of 10^n.
%C A099902 in binary. Bisection of A101623.
%F a(n)=sum{k=0..n, mod(binomial(2n-k, k), 2)10^k}
%K easy,nonn
%O 0,2
%A _Paul Barry_, Dec 11 2004