OFFSET
0,3
COMMENTS
Number of different orderings for n-input trees in a Free Quinary Decision Diagram.
a(7) onward have more than 1000 digits. - G. C. Greubel, Sep 14 2017
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..6
FORMULA
a(0) = 1, a(n) = n*a(n-1)^5.
MATHEMATICA
nxt[{n_, a_}] := {n + 1, (n + 1) a^5}; NestList[nxt, {0, 1}, 5][[All, 2]] (* G. C. Greubel, Sep 14 2017 *)
PROG
(PARI) a(n) = if (n==0, 1, n*a(n-1)^5); \\ Michel Marcus, Sep 14 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
David Willingham (D.Willingham(AT)wmin.ac.uk), Aug 13 2009
STATUS
approved