%I #19 Sep 08 2022 08:45:26
%S 3,1,4,1,4,2,1,3,5,6,2,3,7,3,0,9,5,0,4,8,8,0,1,6,8,8,7,2,4,2,0,9,6,9,
%T 8,0,7,8,5,6,9,6,7,1,8,7,5,3,7,6,9,4,8,0,7,3,1,7,6,6,7,9,7,3,7,9,9,0,
%U 7,3,2,4,7,8,4,6,2,1,0,7,0,3,8,8,5,0,3,8,7,5,3,4,3,2,7,6,4,1,5,7
%N Decimal expansion of 3 + sqrt(2)/10.
%C Said to be Dante Alighieri's approximation to Pi.
%D Jörg Arndt and Christoph Haenel, Pi Unleashed, New York: Springer (2001), p. 56.
%H G. C. Greubel, <a href="/A120731/b120731.txt">Table of n, a(n) for n = 1..10000</a>
%H D. Castellanos, <a href="http://www.jstor.org/stable/2690037">The ubiquitous pi</a>, Math. Mag., 61 (1988), 67-98 and 148-163. [_N. J. A. Sloane_, Mar 24 2012]
%e 3 + sqrt(2)/10 = 3.141421356237309504880168872..., which differs from Pi by 0.00017129735248373485...
%t RealDigits[3 + Sqrt[2]/10, 10, 100][[1]] (* _G. C. Greubel_, Sep 27 2018 *)
%o (PARI) default(realprecision, 100); 3 + sqrt(2)/10 \\ _G. C. Greubel_, Sep 27 2018
%o (Magma) SetDefaultRealField(RealField(100)); 3 + Sqrt(2)/10; // _G. C. Greubel_, Sep 27 2018
%Y Essentially the same sequence as A002193 (sqrt(2)).
%Y Cf. A000796 (Pi).
%K nonn,cons,easy
%O 1,1
%A _Zak Seidov_, Aug 18 2006