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 A247684 #9 Sep 08 2022 08:46:09 %S A247684 1,8,2,3,9,5,9,2,1,6,5,0,1,0,8,2,2,6,8,5,4,6,4,3,3,9,2,7,6,9,1,8,9,4, %T A247684 2,7,8,4,8,5,6,1,7,9,1,8,3,6,7,0,6,2,0,8,8,8,0,1,0,2,0,7,5,0,2,2,8,1, %U A247684 2,0,7,1,9,9,1,3,9,5,6,7,2,5,1,5,5,2,1,1,8,1,6,1,1,0,2,9,9,0,6,6,5,9 %N A247684 Decimal expansion of the integral over the first quadrant (x>0, y>0) of sqrt(x^2 + x*y + y^2)*exp(-x-y) dx dy. %H A247684 G. C. Greubel, <a href="/A247684/b247684.txt">Table of n, a(n) for n = 1..10000</a> %H A247684 D. H. Bailey, J. M. Borwein, <a href="https://escholarship.org/uc/item/4281090t">Highly Parallel, High-Precision Numerical Integration</a> p. 9. (2005) Lawrence Berkeley National Laboratory %F A247684 Equals 1 + (3/4)*log(3). %e A247684 1.8239592165010822685464339276918942784856179183670620888... %t A247684 RealDigits[1 + (3/4)*Log[3], 10, 102] // First %o A247684 (PARI) default(realprecision, 100); (4 + 3*log(3))/4 \\ _G. C. Greubel_, Sep 07 2018 %o A247684 (Magma) SetDefaultRealField(RealField(100)); (4 + 3*Log(3))/4; // _G. C. Greubel_, Sep 07 2018 %Y A247684 Cf. A244921, A247674, A247675, A247677. %K A247684 nonn,cons %O A247684 1,2 %A A247684 _Jean-François Alcover_, Sep 22 2014