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%I #12 Oct 04 2017 00:03:00
%S 1,1,2,6,40320
%N a(n) = (a(n-1) + a(n-2))!.
%C The next term has 168215 digits and is too large to include.
%H J. T. Butler, <a href="/A005607/a005607.pdf">Fanout-free networks of multivalued gates</a>, Proc. Internat. Symposium Multiple-Valued Logic, Charlotte NC, 1977. IEEE Press, NY, 1977, pp. 39-46. (Annotated scanned copy)
%H J. T. Butler, <a href="/A005607/a005607_1.pdf">Letter to N. J. A. Sloane, Dec. 1978</a>
%K nonn,easy
%O 0,3
%A _N. J. A. Sloane_