A322720 - OEIS

%I #9 Apr 08 2019 03:13:01

%S 0,13,85,992,10034,100087,999903,9998042,100003884,999967300

%N Number of times the digit 5 appears in the first 10^n decimal digits of Euler's number e = exp(1), counting starts after the decimal point.

%C It is not known if e is normal, but the distribution of decimal digits found for the first 10^n digits of e shows no statistically significant departure from a uniform distribution.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/eDigits.html">e Digits</a>.

%p a:=proc(n)

%p   local digits, EXP1, C, i;

%p   digits:=10^n+100;

%p   EXP1:=convert(frac(evalf[digits](exp(1))), string)[2..digits-99];

%p   C:=0;

%p   for i from 1 to length(EXP1) do

%p     if EXP1[i]="5" then C:=C+1; fi;

%p   od;

%p   return(C);

%p end;

%t Table[Count[IntegerDigits[IntegerPart[(E - 2)*10^10^n]], 5], {n, 7}] (* _Robert Price_, Apr 07 2019 *)

%Y Cf. A001113, A099296, A322646, A322715, A322716, A322717, A322718, A322719, A322721, A322722, A322723, A322724.

%K nonn,base,more

%O 1,2

%A _Martin Renner_, Dec 24 2018