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 A381752 #9 Mar 06 2025 08:27:54
%S A381752 1,9,525,44067,4338765,467396050,53346810991,6339179481480,
%T A381752 775994115988525,97182642466115275,12392633418043399130,
%U A381752 1603634650155295053250,210047857493659698690575,27795006677556725604853840,3710220786174094422360657000,498998879378383167317202612400
%N A381752 Expansion of exp( Sum_{k>=1} binomial(10*k-1,2*k-1) * x^k/k ).
%F A381752 a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} binomial(10*k-1,2*k-1) * a(n-k).
%o A381752 (PARI) my(N=20, x='x+O('x^N)); Vec(exp(sum(k=1, N, binomial(10*k-1, 2*k-1)*x^k/k)))
%Y A381752 Cf. A006013, A079489, A182960, A381751, A381753, A381757, A381758.
%Y A381752 Cf. A381746.
%K A381752 nonn,easy
%O A381752 0,2
%A A381752 _Seiichi Manyama_, Mar 06 2025