A322649 Number of times the digit 8 appears in the first 10^n decimal digits of sqrt(2), sometimes called Pythagoras's constant, counting after the decimal point.

0, 12, 113, 1027, 10007, 100441, 999452, 9996550, 99995120, 1000025363

Offset

1,2

Comments

It is not known if sqrt(2) is normal, but the distribution of decimal digits found for the first 10^n digits of sqrt(2) shows no statistically significant departure from a uniform distribution.

Links

Table of n, a(n) for n=1..10.

Eric Weisstein's World of Mathematics, Pythagoras's Constant Digits.

Maple

a:=proc(n)
  local digits, SQRT2, C, i;
  digits:=10^n+100;
  SQRT2:=convert(frac(evalf[digits](sqrt(2))), string)[2..digits-99];
  C:=0;
  for i from 1 to length(SQRT2) do
    if SQRT2[i]="8" then C:=C+1; fi;
  od;
  return(C);
end;

Mathematica

Table[DigitCount[IntegerPart[(Sqrt[2]-1)*10^10^n], 10, 8], {n, 1, 10}] (* Robert Price, Mar 29 2019 *)

Crossrefs

Cf. A002193, A099299, A322641, A322642, A322643, A322644, A322645, A322646, A322647, A322648, A322650.

Sequence in context: A285154 A153882 A357650 * A198375 A124651 A231379

Adjacent sequences: A322646 A322647 A322648 * A322650 A322651 A322652

Keyword

nonn,base,more

Author

Martin Renner, Dec 21 2018

Status

approved