A071982 - OEIS

%I #14 Aug 12 2024 02:46:23

%S 1,0,1,0,0,1,1,1,0,0,1,1,1,0,1,1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,1,0,1,0,

%T 0,1,0,1,0,1,0,1,1,0,1,1,1,1,0,1,0,0,0,1,1,1,1,0,0,1,1,1,1,1,1,1,0,1,

%U 1,0,0,1,0,0,0,0,1,0,1,0,1,0,0,1,0,1,0,1,1,1,0,1,0,1,0,0,1,1,1,0,1,1,1,0,1

%N Parity of the decimal digits of sqrt(2).

%H G. C. Greubel, <a href="/A071982/b071982.txt">Table of n, a(n) for n = 0..10000</a>

%t  Table[(1 - (-1)^Floor[10^n*Sqrt[2]])/2, {n, 0, 100}] (* _G. C. Greubel_, Oct 01 2018 *)

%o (PARI) \p200 for(n=0,150,print1((1-(-1)^floor(10^n*sqrt(2)))/2,","))

%o (PARI) a(n)=if(n<0,0,sqrtint(2*100^n)%2)

%o (Magma) [(1 - (-1)^Floor(10^n*Sqrt(2)))/2: n in [0..100]]; // _G. C. Greubel_, Oct 01 2018

%Y Cf. A001113, A002193, A030657.

%K easy,nonn,base

%O 0,1

%A _Benoit Cloitre_, Jun 25 2002