This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A366248 #22 Nov 07 2023 05:00:50 %S A366248 2,5,8,0,6,9,7,5,8,0,1,1,2,7,8,8,0,3,1,5,1,8,8,4,2,0,6,0,5,1,4,9,1,4, %T A366248 0,8,9,6,0,8,2,6,0,6,6,7,1,8,7,2,2,0,6,8,5,8,5,2,4,1,3,6,9,2,3,7,1,2, %U A366248 2,8,0,8,0,3,9,8,9,0,5,1,0,3,8,3,4,9,9 %N A366248 Decimal expansion of sqrt(666). %D A366248 C. A. Pickover, The Mathematics of Oz, pp. 274, Cambridge University Press 2002. %H A366248 Paolo Xausa, <a href="/A366248/b366248.txt">Table of n, a(n) for n = 2..10000</a> %e A366248 25.80697580112788031518842060514914089608260667187220685852413692371228... %t A366248 First[RealDigits[Sqrt[666], 10, 100]] (* Paolo Xausa, Nov 06 2023 *) %o A366248 (PARI) \\ Works in v2.13 and higher; n = 100 decimal places %o A366248 my(n=100); digits(floor(10^n*quadgen(2664))) \\ _Michal Paulovic_, Oct 14 2023 %o A366248 (Python) %o A366248 from math import isqrt %o A366248 def A366248(n): return (isqrt(666//10**(3-n<<1)) if n<3 else isqrt(666*10**(n-3<<1))) % 10 # _Chai Wah Wu_, Nov 06 2023 %Y A366248 Cf. A040640 (continued fraction), A021670. %K A366248 nonn,cons,easy %O A366248 2,1 %A A366248 _Jack Zhang_, Oct 05 2023