A375820 - OEIS

%I #14 Aug 31 2024 01:57:12

%S 3,1,4,1,5,0,9,4,3,3,9,6,2,2,6,4,1,5,0,9,4,3,3,9,6,2,2,6,4,1,5,0,9,4,

%T 3,3,9,6,2,2,6,4,1,5,0,9,4,3,3,9,6,2,2,6,4,1,5,0,9,4,3,3,9,6,2,2,6,4,

%U 1,5,0,9,4,3,3,9,6,2,2,6,4,1,5,0,9,4,3,3,9,6,2,2,6,4,1,5,0,9,4,3

%N Decimal expansion of 333/106.

%C Approximation of Pi accurate up to five digits.

%C Periodic of period [4, 1, 5, 0, 9, 4, 3, 3, 9, 6, 2, 2, 6] of length 13.

%D David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987. See p. 49.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Adriaan_Metius">Adriaan Metius</a>.

%H <a href="/index/Rec#order_13">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,0,0,0,1).

%F Equals (2*355 - 377)/(2*113 - 120), where A068079 = 355/113 and A210622 = 377/120 [Adriaen Metius]. See Wells.

%e 3.1415094339622641509433962264150943396226415...

%t RealDigits[333/106,10,100][[1]]

%o (Python)

%o def A375820(n): return (2, 2 ,6, 4, 1, 5, 0, 9, 4, 3, 3, 9, 6)[n%13] if n>2 else 5-(n<<1) # _Chai Wah Wu_, Aug 30 2024

%Y Cf. A000796, A068079, A210622.

%K nonn,cons,easy

%O 1,1

%A _Stefano Spezia_, Aug 30 2024