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 A002399 M5015 N2160 #23 Oct 15 2023 00:25:06
%S A002399 1,16,177,5548,39615,2236440,40325915,1207505768,13229393814,
%T A002399 1737076976040,22446050738265,4058838484620084,60476452041557409,
%U A002399 961082989270516112,32455938583801467735,9864953815464307351792,186195769473110823077652,70295408103581008790661648,1466826914074651870368663750
%N A002399 Coefficients for step-by-step integration.
%C A002399 These are the negated coefficients of f(x_{-1}) in the estimate for y(x1) - y(x0).
%D A002399 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002399 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A002399 Jack W Grahl, <a href="/A002399/b002399.txt">Table of n, a(n) for n = 1..100</a>
%H A002399 Jack W Grahl, <a href="/A002405/a002405.pdf">Explanation of how the sequence was calculated</a>.
%H A002399 Jack W Grahl, <a href="/A002405/a002405.py.txt">Python code to calculate this and related sequences</a>.
%H A002399 W. F. Pickard, <a href="https://doi.org/10.1145/321217.321226">Tables for the step-by-step integration of ordinary differential equations of the first order</a>, J. ACM 11 (1964), 229-233.
%H A002399 W. F. Pickard, <a href="/A002397/a002397.pdf">Tables for the step-by-step integration of ordinary differential equations of the first order</a>, J. ACM 11 (1964), 229-233. [Annotated scanned copy]
%Y A002399 Column 1 (negated) of A260780.
%Y A002399 The following sequences are taken from page 231 of Pickard (1964): A002397, A002398, A002399, A002400, A002401, A002402, A002403, A002404, A002405, A002406, A260780, A260781.
%K A002399 nonn
%O A002399 1,2
%A A002399 _N. J. A. Sloane_
%E A002399 More terms from _Jack W Grahl_, Feb 28 2021