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%I #13 Oct 18 2024 18:55:03
%S 1,4,20,1620,2626020,34479907828020,10699776394458828344981911620,
%T 228970429782836729250563232145698649718622958323963960420,
%U 314564746289621790478499809054644383073494124885364231904506529162346525698245870188461228508418377184391923418820
%N a(n) is the denominator of the sum S(n) defined in A376048.
%H Alois P. Heinz, <a href="/A376049/b376049.txt">Table of n, a(n) for n = 0..11</a>
%F a(n+1) = b(n+1)*a(n)^2 + a(n), with a(1) = 4, where b(n) is defined in A376048.
%e The first few values of S(n) are 0/1, 3/4, 19/20, 1619/1620, 2626019/2626020, 34479907828019/34479907828020, ...
%Y Cf. A000796, A375531, A375532, A376048.
%K nonn,base,frac
%O 0,2
%A _N. J. A. Sloane_, Sep 13 2024.
%E a(0)=1 prepended by _Alois P. Heinz_, Oct 18 2024