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 A000176 M2001 N0791 #31 Jul 28 2024 10:05:52
%S A000176 2,11,46,128,272,522,904,1408,2160,3154,4306,5888,7888,10012,12888,
%T A000176 16384,19680,24354,29866,34816,41888,49778,56744,66816,78000,87358,
%U A000176 100602,115712,128112,145804,165712,180224,203040,228964,246932,276480
%N A000176 Generalized tangent numbers d_(n,2).
%C A000176 Consider the Dirichlet series L_a(s) = sum_{k>=0} (-a|2k+1) / (2k+1)^s, where (-a|2k+1) is the Jacobi symbol. Then the numbers d_(a,n) are defined by L_a(2n)= (Pi/(2a))^(2n)*sqrt(a)* d_(a,n)/ (2n-1)! for a>1 and n=1,2,3...
%D A000176 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A000176 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A000176 Sean A. Irvine, <a href="/A000176/b000176.txt">Table of n, a(n) for n = 1..10000</a>
%H A000176 D. Shanks, <a href="http://dx.doi.org/10.1090/S0025-5718-1967-0223295-5">Generalized Euler and class numbers</a>. Math. Comp. 21 (1967) 689-694.
%H A000176 D. Shanks, <a href="http://dx.doi.org/10.1090/S0025-5718-1968-0227093-9">Corrigenda to: "Generalized Euler and class numbers"</a>, Math. Comp. 21 (1967), 689-694; 22 (1968), 699.
%Y A000176 Cf. A000061 for d_(n,1), A000488 for d_(n,3), A000518 for d_(n,4).
%K A000176 nonn
%O A000176 1,1
%A A000176 _N. J. A. Sloane_
%E A000176 More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jun 03 2000