A322642 Number of times the digit 1 appears in the first 10^n decimal digits of sqrt(2), sometimes called Pythagoras's constant, counting after the decimal point.

2, 7, 98, 1005, 10106, 98924, 1000114, 10000179, 99998381, 1000042849

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

Mathematica

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

Crossrefs

Cf. A002193, A099292, A322641, A322643, A322644, A322645, A322646, A322647, A322648, A322649, A322650.

Sequence in context: A002812 A219280 A277434 * A192342 A102598 A206157

Adjacent sequences: A322639 A322640 A322641 * A322643 A322644 A322645

Keyword

nonn,base,more

Author

Martin Renner, Dec 21 2018

Status

approved