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 A145962 #24 Feb 16 2025 08:33:09 %S A145962 2,0,5,0,0,2,5,5,7,6,3,6,4,2,3,5,3,3,9,4,4,1,5,0,3,3,6,2,1,8,4,9,2,2, %T A145962 6,6,9,0,6,1,6,5,2,4,2,7,1,2,1,4,9,4,3,9,6,0,0,0,1,8,5,0,6,3,4,7,8,0, %U A145962 9,8,9,5,8,6,1,2,0,9,3,0,1,4,5,4,5,0,7,6,4,1,6,9,2,8,2,2,9,0,3,3 %N A145962 Decimal expansion of (1/5)*Hypergeometric2F1[1, 5/8, 13/8, 1/16] used in BBP Pi formula. %C A145962 BBP formula for Pi = 4*A145963 - (1/2)*A145960 - (1/2)*A145961 - A145962. %H A145962 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BBPFormula.html">BBP Formula</a> %F A145962 Equals Sum_{k>=0} (1/16)^k / (8*k+5). %e A145962 0.2050025576364235339441503362184922669061652427121494396000185063478... %t A145962 RealDigits[1/5 Hypergeometric2F1[1, 5/8, 13/8, 1/16], 10, 100][[1]] %t A145962 N[Sum[(1/16)^n (1/(8n+5)),{n,0,Infinity}], 100] %t A145962 N[Sqrt[2](ArcCot[Sqrt[2]] + ArcCoth[Sqrt[2]]) -Pi/4 - ArcCot[3] - Log[5]/2, 100] %o A145962 (PARI) suminf(k=0, (1/16)^k / (8*k+5)) \\ _Michel Marcus_, Jan 16 2021 %Y A145962 Cf. A000796, A145960, A145961, A145963. %K A145962 cons,nonn %O A145962 0,1 %A A145962 _Artur Jasinski_, Oct 25 2008 %E A145962 Leading zero removed, offset adjusted by _R. J. Mathar_, Feb 05 2009