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 A384738 #18 Jun 15 2025 22:16:37 %S A384738 1,2,7,1,6,1,3,0,3,7,2,1,2,3,4,8,2,7,2,5,5,0,9,3,6,6,8,1,8,3,6,9,4,5, %T A384738 6,5,5,3,1,9,7,8,9,2,5,8,4,8,3,0,3,2,1,2,9,6,8,6,4,1,9,3,3,0,8,1,5,6, %U A384738 8,1,6,5,6,9,1,4,9,4,9,1,1,8,7,5,8,9,3 %N A384738 Decimal expansion of 3*log(2)/4 - Pi/8. %C A384738 Generalization of infinite sum generating A002162 (natural logarithm of 2). That sum is Sum_{i >= 1} 1/(k*i-1) - 1/(k*i), where k = 2. Here, we set k = 4. %H A384738 Jason Bard, <a href="/A384738/b384738.txt">Table of n, a(n) for n = 0..9999</a> %H A384738 Steve Chow (Blackpenredpen), <a href="https://www.youtube.com/watch?v=4RfLtYDzqoc">Not telescoping: series of 1/(4n-1)-1/(4n)</a> (2019), YouTube video. %H A384738 Michael I. Shamos, <a href="http://euro.ecom.cmu.edu/people/faculty/mshamos/cat.pdf">A catalog of the real numbers</a>, (2007). See p. 166. %F A384738 Equals Sum_{k>=1} (1/(4k-1) - (1/4k)). %F A384738 Equals Sum_{k>=2} zeta(k)/4^k. %F A384738 Equals Integral_{x=1..oo} 1/(x^4+x^3+x^2+x) dx. %F A384738 Equals A100046/2. - _Amiram Eldar_, Jun 09 2025 %e A384738 0.12716130372123482725509366818369456553197892584830... %t A384738 RealDigits[3/4*Log[2] - Pi/8, 10, 140][[1]] %o A384738 (PARI) 3*log(2)/4 - Pi/8 \\ _Amiram Eldar_, Jun 09 2025 %Y A384738 Cf. A002162, A100046, A384683. %K A384738 nonn,cons %O A384738 0,2 %A A384738 _Jason Bard_, Jun 08 2025