cp's OEIS Frontend

A155912 Let d(i) be the i-th digit of the decimal expansion of Pi = 3.1415926535897932384626433832795..., so that d(0) = 3, d(1) = 1, d(2) = 4, etc. Then a(0) = 3, a(n) = d(d(n)) for n>0.

%I A155912 #8 Aug 01 2015 10:36:47
%S A155912 3,1,5,1,9,3,4,2,9,1,9,5,3,6,3,1,4,1,5,5,2,4,2,5,1,1,5,1,4,6,3,9,3,4,
%T A155912 5,5,5,1,3,6,1,2,3,1,3,3,1,6,9,1,3,9,5,4,3,3,6,5,3,5,5,9,3,4,1,3,6,5,
%U A155912 1,2,5,3,2,4,5,2,4,3,5,3,3,5,2,4,5,3,1,5,5,4,9,1,5,4,1,1,6,3,2,6,3,5,4,1,5
%N A155912 Let d(i) be the i-th digit of the decimal expansion of Pi = 3.1415926535897932384626433832795..., so that d(0) = 3, d(1) = 1, d(2) = 4, etc. Then a(0) = 3, a(n) = d(d(n)) for n>0.
%C A155912 This defines a constant 3.151934291953631... related to Pi in a peculiar way!
%H A155912 Zak Seidov, <a href="/A155912/b155912.txt">Table of n, a(n) for n = 0..999</a>
%t A155912 id = Rest@ RealDigits[ Pi, 10, 105][[1]]; id[[0]] = 3; id[[ id[[ 0]]]] = 3; Table[id[[ id[[ n]]]], {n, 0, 104}] (* _Robert G. Wilson v_, Mar 17 2009 *)
%Y A155912 Cf. A135725.
%Y A155912 Cf. A119505. - _Robert G. Wilson v_, Mar 17 2009
%K A155912 nonn,base
%O A155912 0,1
%A A155912 Dan Brown (ddbhockey(AT)hotmail.com), Jan 30 2009
%E A155912 Edited and extended by _Zak Seidov_ and _N. J. A. Sloane_, Feb 10 2009
%E A155912 Sequence corrected by _N. J. A. Sloane_ Aug 31 2009 using terms from the b-file