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 A256425 #32 Feb 03 2025 09:45:45 %S A256425 6,7,7,8,0,7,1,6,3,7,8,4,2,3,2,2,1,0,5,3,3,7,2,4,6,1,2,4,5,4,9,1,4,3, %T A256425 8,3,1,6,9,3,1,2,5,7,9,6,3,2,5,5,6,2,0,4,1,5,2,6,8,5,6,2,3,1,3,2,5,5, %U A256425 8,8,2,1,3,1,6,7,1,5,3,6,5,4,0,5,2,7,2,4,7,8,2,6,8,2,1,4,2,9 %N A256425 Decimal expansion of the generalized Euler constant gamma(1,3). %D A256425 Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.5.3, p. 32. %H A256425 G. C. Greubel, <a href="/A256425/b256425.txt">Table of n, a(n) for n = 0..5000</a> %H A256425 D. H. Lehmer, <a href="http://matwbn.icm.edu.pl/ksiazki/aa/aa27/aa27121.pdf">Euler constants for arithmetic progressions</a>, Acta Arith. 27 (1975), 125-142. [gamma=A001620, gamma(0,2)=A239097, gamma(1,2)=A228725, N_k=A007947, gamma(1,3)=A256425, the present sequence] %F A256425 Equals gamma/3+Pi*sqrt(3)/18+log(3)/6. %F A256425 Equals -(psi(1/3) + log(3))/3 = (A047787 - A002391)/3. - _Amiram Eldar_, Jan 07 2024 %e A256425 0.67780716378423221053372461245491438316931257963255620415268... %t A256425 RealDigits[EulerGamma/3 + Pi*Sqrt[3]/18 + Log[3]/6, 10, 50][[1]] (* _G. C. Greubel_, Jun 08 2017 *) %o A256425 (PARI) Euler/3 + Pi*sqrt(3)/18 + log(3)/6 \\ _Charles R Greathouse IV_, Sep 08 2015 %o A256425 (PARI) -(psi(1/3) + log(3))/3 \\ _Charles R Greathouse IV_, Feb 03 2025 %Y A256425 Cf. A001620, A002391, A007947, A047787, A228725, A239097. %K A256425 nonn,cons %O A256425 0,1 %A A256425 _N. J. A. Sloane_, Apr 09 2015