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%I #15 May 14 2016 19:21:09
%S 1,1,1,2,6,22,95,463,2483,14426,89799,594038,4150514,30482791,
%T 234428282,1881944298,15729230166,136566166388,1229346044429,
%U 11454129882773,110293243452027,1096078120808889,11227947692444477,118421577443291274,1284625091089249880
%N G.f. satisfies A(x) = 1 + x*A(x*A(x*A(x))).
%H Alois P. Heinz, <a href="/A087959/b087959.txt">Table of n, a(n) for n = 0..100</a>
%p A:= proc(n) option remember; local T; if n=0 then 1 else T:= A(n-1); unapply(convert(series(1+ x*T(x*T(x*T(x))), x, n+1), polynom), x) fi end: a:= n-> coeff(A(n)(x), x, n): seq(a(n), n=0..21); # _Alois P. Heinz_, Aug 23 2008
%t A[n_] := A[n] = Module[{T}, If[n == 0, 1, T[y_] = A[n-1][y]; Normal[Series[1+x*T[x*T[x*T[x]]], {x, 0, n+1}]] /. x -> #]&]; a[n_] := Coefficient[A[n][x], x, n]; Table [a[n], {n, 0, 24}] (* _Jean-François Alcover_, Feb 14 2014, after _Alois P. Heinz_ *)
%Y Cf. A087949.
%K nonn
%O 0,4
%A _Paul D. Hanna_, Sep 16 2003
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