%I A129344
%S A129344 4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,3,4,3,3,4,
%T A129344 3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,3,4,3,3,4,3,3,4,3,3,4,3,
%U A129344 3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,4,3,3,3,4,3,3
%N A129344 a(n) is the number of powers of 2 that have n decimal digits.
%e A129344 a(1) is 4 because there are 4 one-digit powers of 2: 1, 2, 4, 8.
%t A129344 Table[Transpose[ Select[Table[{n, 2^n}, {n, 0, 310}], IntegerDigits[ 
               #[[2]]][[1]] == 1 &]][[1]][[k]] - Transpose[ Select[Table[{n, 2^n}, 
               {n, 0, 310}], IntegerDigits[ #[[2]]][[1]] == 1 &]][[1]][[k - 1]], 
               {k, 2, 94}]
%Y A129344 The difference of A067497 - Smallest power of 2 with n+1 digits (n>=0). 
               Also n such that 1 is the first digit of 2^n.
%Y A129344 Sequence in context: A085415 A059124 A026858 this_sequence A048853 A011762 
               A063571
%Y A129344 Adjacent sequences: A129341 A129342 A129343 this_sequence A129345 A129346 
               A129347
%K A129344 base,nonn
%O A129344 1,1
%A A129344 Tanya Khovanova (tanyakh(AT)yahoo.com), May 28 2007