A322644 Number of times the digit 3 appears in the first 10^n decimal digits of sqrt(2), sometimes called Pythagoras's constant, counting after the decimal point.

2, 11, 82, 980, 10058, 100191, 999674, 10004178, 99995415, 999984900

Offset

1,1

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]="3" then C:=C+1; fi;
  od;
  return(C);
end;

Mathematica

Table[DigitCount[IntegerPart[(Sqrt[2]-1)*10^10^n], 10, 3], {n, 1, 10}] (* Robert Price, Mar 29 2019 *)

Crossrefs

Cf. A002193, A099294, A322641, A322642, A322643, A322645, A322646, A322647, A322648, A322649, A322650.

Sequence in context: A330677 A209094 A293574 * A243408 A352655 A104086

Adjacent sequences: A322641 A322642 A322643 * A322645 A322646 A322647

Keyword

nonn,base,more

Author

Martin Renner, Dec 21 2018

Status

approved