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a(1)=a(2)=a(3)=1; for n > 3, a(n) = a(n-1)*a(n-2)*a(n-3) + a(n-1) + a(n-2) + a(n-3).
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%I #9 Dec 21 2023 15:05:35

%S 1,1,1,4,10,55,2269,1250284,156030444388,442641893445738546589,

%T 86351628807475712878787449679327520349,

%U 5963928033713995675288097975918984841058670353057557384156171322944994

%N a(1)=a(2)=a(3)=1; for n > 3, a(n) = a(n-1)*a(n-2)*a(n-3) + a(n-1) + a(n-2) + a(n-3).

%t a[1] = 1; a[2] = 1; a[3] = 1;

%t a[n_] := a[n] = a[n - 1]*a[n - 2]*a[n - 3] + a[n - 1] + a[n - 2] + a[n - 3];

%t Table[a[n], {n, 1, 12}]

%Y Cf. A063896 (a(n) = a(n-1)*a(n-2) + a(n-1) + a(n-2)), A000073.

%K nonn

%O 1,4

%A _José María Grau Ribas_, Nov 18 2023