%I #3 Mar 30 2012 18:50:42
%S 2,1,5,1,5,5,5,5,5,5,1,21,21,21,5,21,5,5,5,5,21,5,21,21,5,21,5,21,21,
%T 5,1,5,21,21,85,21,21,21,21,85,21,85,5,5,21,5,21,5,5,21,21,5,5,5,5,5,
%U 21,5,85,21,21,85,21,21,21,21,85,85,85,85,21,21,21,85,21,5,21,21,21
%N In binary expansion of n-th prime: reduce contiguous blocks of 0's to 0 and contiguous blocks of 1's to 1.
%C a(n) = A090079(A000040(n)).
%e A000040(25)=97 -> '1100001' -> [11][0000][1] -> [1][0][1] ->
%e '101' -> 5=a(25).
%Y Cf. A004676.
%K nonn,base
%O 1,1
%A _Reinhard Zumkeller_, Nov 20 2003
|