login
"Memory" of 2^n: the number of (previous) powers of 2 contained as substrings in 2^n.
0

%I #2 Feb 11 2014 19:05:41

%S 0,0,0,0,1,1,2,1,1,2,3,1,2,3,3,0,1,2,3,2,1,1,1,2,3,3,3,3,2,3,4,2,3,2,

%T 2,2,3,3,2,2,2,2,2,4,4,3,4,3,2,3,3,2,2,2,2,2,3,3,4,3,3,4,3,3,4,4,4,3,

%U 2,4,4,4,3,2,3,4,4,2,3,3,4,5,3,4,3,4,3,3,4,3,3,4,3,3,5,5,4,4,4,4

%N "Memory" of 2^n: the number of (previous) powers of 2 contained as substrings in 2^n.

%t lb = 1; ub = 100; tt = Table[ToString[2^i], {i, 1, ub}]; a = {}; For[i = lb, i <= ub, i++, m = 0; For[j = 1, j < i, j++, If[Length[StringPosition[tt[[i]], tt[[j]]]] > 0, m = m + 1]]; a = Append[a, m]]; a

%K base,easy,nonn

%O 1,7

%A _Joseph L. Pe_, Feb 03 2003