%I #7 Nov 21 2013 12:48:42

%S 4,9,6,5,8,9,9,8,6,6,8,7,9,5,8,8,9,7,6,9,9,9,7,5,5,8,9,7,9,9,3,7,8,6,

%T 4,6,8,6,8,9,9,8,6,8,3,8,5,4,7,6,9,8,8,8,5,3,8,3,6,6,7,9,8,6,9,5,5,8,

%U 3,7,5,9,8,8,8,7,5,8,7,9,8,1,5,9,6,9,8,9,9,8,9,4,8,8,9,6,6,9,4,6,8,7,6,8,3

%N Strong digits in the decimal expansion of Pi.

%C In the decimal expansion of Pi, balanced digits are much more rare than weak or strong ones.

%e In the decimal expansion of Pi: 3,1,4,1,5,9,2,6,5,3,5,8,9,7,9,3,2,3,8,4,6,2, the first two strong digits are 4 and 9 because 4>(1+1)/2 and 9>(5+2)/2.

%t re=RealDigits[N[Pi, 300]][[1]];b={};Do[r=re[[n]];If[r>(re[[n-1]]+re[[n+1]])/2, b=Append[b, r]], {n, 2, 299}];A108533=b

%t sdQ[{a_,b_,c_}]:=b>Mean[{a,c}]; Transpose[Select[Partition[RealDigits[ Pi,10,300][[1]],3,1],sdQ]][[2]] (* _Harvey P. Dale_, Nov 12 2011 *)

%Y Cf. A108534 (weak digits), A108535 (positions of balanced digits).

%K nonn,base

%O 1,1

%A _Zak Seidov_, Jun 08 2005