A322647 Number of times the digit 6 appears in the first 10^n decimal digits of sqrt(2), sometimes called Pythagoras's constant, counting after the decimal point.

1, 10, 90, 1032, 9939, 99886, 1001246, 10001665, 100012683, 1000007824

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]="6" then C:=C+1; fi;
  od;
  return(C);
end;

Mathematica

Table[DigitCount[IntegerPart[(Sqrt[2]-1)*10^10^n], 10, 6], {n, 1, 10}] (* Robert Price, Mar 29 2019 *)
Table[Count[RealDigits[Sqrt[2], 10, 10^n][[1]], 6], {n, 10}] (* Harvey P. Dale, Oct 02 2022 *)

Crossrefs

Cf. A002193, A099297, A322641, A322642, A322643, A322644, A322645, A322646, A322648, A322649, A322650.

Sequence in context: A172199 A063945 A218127 * A243106 A046706 A337867

Adjacent sequences: A322644 A322645 A322646 * A322648 A322649 A322650

Keyword

nonn,base,more

Author

Martin Renner, Dec 21 2018

Status

approved