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A082168 a(n) = A006690(n)/n^3. 1
1, 7, 295, 33251, 7319436, 2669857476, 1459913038884, 1118904543734724, 1145415466062268695, 1510492370204314777345, 2494718462461802382223714 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
REFERENCES
Valery A. Liskovets, The number of initially connected automata, Kibernetika, (Kiev), No3 (1969), 16-19; Engl. transl.: Cybernetics, v.4 (1969), 259-262.
LINKS
Valery A. Liskovets, Exact enumeration of acyclic automata, Proc. 15th Conf. "Formal Power Series and Algebr. Combin. (FPSAC'03)", 2003.
Valery A. Liskovets, Exact enumeration of acyclic deterministic automata, Discrete Appl. Math., 154, No.3 (2006), 537-551.
FORMULA
a(n) := A006690(n)/n^3
MATHEMATICA
b[1] = 1; b[n_] := b[n] = n^(3n)/(n-1)! - Sum[n^(3(n-i)) b[i]/(n-i)!, {i, 1, n-1}];
a[n_] := b[n]/n^3;
Array[a, 11] (* Jean-François Alcover, Aug 28 2019 *)
CROSSREFS
Cf. A006690.
Sequence in context: A137435 A220241 A041851 * A362658 A096348 A281435
KEYWORD
easy,nonn
AUTHOR
Valery A. Liskovets, Apr 09 2003
STATUS
approved

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Last modified March 4 07:29 EST 2024. Contains 370522 sequences. (Running on oeis4.)