cp's OEIS Frontend

A135725 Let d(i) be the i-th digit of the decimal expansion of e = 2.718281828459045235360287471352662..., so that d(0) = 2, d(1) = 7, d(2) = 1, etc. Then a(0) = 2, a(n) = d(d(n)) for n>0.

%I A135725 #6 Mar 30 2012 16:50:47
%S A135725 2,8,7,2,1,2,7,2,1,2,2,8,8,2,2,8,1,8,8,8,1,2,1,2,8,2,8,7,8,8,1,1,1,1,
%T A135725 2,8,8,8,8,8,1,2,8,2,8,8,1,8,8,8,8,8,8,8,2,8,1,1,8,1,8,1,1,8,8,1,2,2,
%U A135725 8,1,1,8,2,8,8,8,8,2,8,8,8,2,8,8,7,8,2,1,7,8,2,8,1,8,7,1,1,2,1
%N A135725 Let d(i) be the i-th digit of the decimal expansion of e = 2.718281828459045235360287471352662..., so that d(0) = 2, d(1) = 7, d(2) = 1, etc. Then a(0) = 2, a(n) = d(d(n)) for n>0.
%C A135725 This defines a constant 2.8721272122882... related to e in a peculiar way!
%H A135725 Zak Seidov, <a href="/A135725/b135725.txt">Table of n, a(n) for n = 0..999</a>
%Y A135725 Cf. A155912.
%K A135725 nonn,base
%O A135725 0,1
%A A135725 Zak Seidov and _N. J. A. Sloane_, Feb 10 2009