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 A002673 M4894 N2097 #33 Feb 16 2025 08:32:26
%S A002673 1,1,13,41,671,73,597871,7913,28009,792451,170549237,19397633,
%T A002673 317733228541,9860686403,75397891,170314355593,2084647712458321,
%U A002673 29327731093,168856464709124011,3063310184201,499338236699611,535201577273701757,23571643935246013553
%N A002673 Numerators of central difference coefficients M_{3}^(2n+1).
%C A002673 From _Peter Bala_, Oct 03 2019: (Start)
%C A002673 Numerators in the expansion of (2*sinh(x/2))^3 = x^3 + (1/8)*x^5 + (13/1920)*x^7 + (41/193536)*x^9 + ....
%C A002673 Let f(x) be a polynomial in x. The expansion of (2*sinh(x/2))^3 leads to a formula for the third central differences: f(x+3/2) - 3*f(x+1/2) + 3*f(x-1/2) - f(x-3/2) = (2*sinh(D/2))^3(f(x)) = D^3(f(x)) + (1/8)*D^5(f(x)) + (13/1920)* D^7(f(x)) + ..., where D denotes the differential operator d/dx. (End)
%D A002673 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002673 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A002673 H. E. Salzer, <a href="https://doi.org/10.1002/sapm1963421162">Tables of coefficients for obtaining central differences from the derivatives</a>, Journal of Mathematics and Physics (this journal is also called Studies in Applied Mathematics), 42 (1963), 162-165, plus several inserted tables.
%H A002673 H. E. Salzer, <a href="/A002673/a002673.png">Annotated scanned copy of left side of Table I</a>.
%H A002673 E. W. Weisstein, <a href="https://mathworld.wolfram.com/CentralDifference.html">Central Difference</a>. From MathWorld--A Wolfram Web Resource.
%Y A002673 Cf. A002671, A002672, A002674, A002675, A002676, A002677.
%K A002673 nonn,frac
%O A002673 1,3
%A A002673 _N. J. A. Sloane_