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 A238181 #11 May 22 2025 16:42:24 %S A238181 1,6,5,1,9,4,2,7,9,2,7,0,4,4,9,8,6,2,3,9,6,2,6,9,3,7,6,1,1,1,4,4,9,4, %T A238181 0,1,6,1,1,7,6,3,1,7,5,1,5,9,6,5,6,0,6,3,3,2,1,3,8,5,2,0,9,5,6,0,8,5, %U A238181 9,7,5,3,0,1,0,5,3,8,0,9,8,8,2,5,7,7,6,6,5,0,0,4,2,8,2,1,7,0,6,9 %N A238181 Decimal expansion of sum_(n>=1) H(n)^2/n^3 where H(n) is the n-th harmonic number (Quadratic Euler Sum S(2,3)). %H A238181 Philippe Flajolet, Bruno Salvy, <a href="http://algo.inria.fr/flajolet/Publications/FlSa98.pdf">Euler Sums and Contour Integral Representations</a>, Experimental Mathematics 7:1 (1998) page 24. %F A238181 7/2*zeta(5) - zeta(2)*zeta(3). %e A238181 1.6519427927044986239626937611144940161... %t A238181 7/2*Zeta[5] - Zeta[2]*Zeta[3] // RealDigits[#, 10, 100]& // First %o A238181 (PARI) 7/2*zeta(5) - zeta(2)*zeta(3) \\ _Stefano Spezia_, May 22 2025 %Y A238181 Cf. A152648, A152649, A152651, A218505, A238168, A238182, A238183. %K A238181 nonn,cons %O A238181 1,2 %A A238181 _Jean-François Alcover_, Feb 19 2014