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 A049392 #13 Jan 16 2020 08:45:52
%S A049392 1,-10,-75,-1000,-16250,-292500,-5606250,-112125000,-2312578125,
%T A049392 -48821093750,-1049653515625,-22901531250000,-505742148437500,
%U A049392 -11281940234375000,-253843655273437500,-5753789519531250000
%N A049392 Expansion of (1-25*x)^(2/5).
%H A049392 Iain Fox, <a href="/A049392/b049392.txt">Table of n, a(n) for n = 0..718</a>
%F A049392 G.f.: (1-25*x)^(2/5).
%F A049392 a(n) = (5^n/n!) * Product_{k=0..n-1} (5*k-2).
%F A049392 a(n) ~ -2/5*Gamma(3/5)^-1*n^(-7/5)*5^(2*n)*{1 + 7/25*n^-1 + ...}. - Joe Keane (jgk(AT)jgk.org), Nov 24 2001
%e A049392 (1-x)^(2/5) = 1 - 2/5*x - 3/25*x^2 - 8/125*x^3 - ...
%o A049392 (PARI) first(n) = x='x+O('x^n); Vec((1-25*x)^(2/5)) \\ _Iain Fox_, Aug 10 2018
%Y A049392 Cf. A049381.
%K A049392 sign,easy
%O A049392 0,2
%A A049392 Joe Keane (jgk(AT)jgk.org)
%E A049392 Definition corrected by _Georg Fischer_, Jan 16 2020