A108533 - OEIS

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A108533

Strong digits in the decimal expansion of Pi.

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, 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, 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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

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

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

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.

MATHEMATICA

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

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 *)

CROSSREFS

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

Sequence in context: A169917 A059729 A184988 * A200414 A347215 A248866

Adjacent sequences: A108530 A108531 A108532 * A108534 A108535 A108536

KEYWORD

nonn,base

AUTHOR

Zak Seidov, Jun 08 2005

STATUS

approved