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A322645 Number of times the digit 4 appears in the first 10^n decimal digits of sqrt(2), sometimes called Pythagoras's constant, counting after the decimal point. 10
2, 9, 100, 1016, 10100, 100024, 1000126, 10000054, 100012725, 1000008724 (list; graph; refs; listen; history; text; internal format)
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
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]="4" then C:=C+1; fi;
od;
return(C);
end;
MATHEMATICA
Table[DigitCount[IntegerPart[(Sqrt[2]-1)*10^10^n], 10, 4], {n, 1, 10}] (* Robert Price, Mar 29 2019 *)
CROSSREFS
Sequence in context: A360696 A357825 A187647 * A368725 A277180 A013520
KEYWORD
nonn,base,more
AUTHOR
Martin Renner, Dec 21 2018
STATUS
approved

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Last modified March 28 21:57 EDT 2024. Contains 371254 sequences. (Running on oeis4.)