A002824 Number of precomplete Post functions.

1, 3, 18, 190, 3285, 88851, 3640644, 220674924, 19427552055, 2448107338105, 436330306419678, 108909970814260122, 37752710546082668409, 18044326480066641231855, 11818118910855384843861960, 10549135258779933616014791704, 12772521057179994145518171256587

Offset: 2

Author

N. J. A. Sloane

Keywords

• nonn

References

• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
• E. Ju. Zaharova, V. B. Kudrjavcev, and S. V. Jablonskii, Precomplete classes in k-valued logics. (Russian) Dokl. Akad. Nauk SSSR 186 (1969), 509-512. English translation in Soviet Math. Doklady 10 (No. 3, 1969), 618-622.

Links

• Ivo Rosenberg, The number of maximal closed classes in the set of functions over a finite domain, J. Combinatorial Theory Ser. A 14 (1973), 1-7.
• Ivo Rosenberg and N. J. A. Sloane, Correspondence, 1971
• E. Ju. Zaharova, V. B. Kudrjavcev, and S. V. Jablonskii, Precomplete classes in k-valued logics. (Russian), Dokl. Akad. Nauk SSSR 186 (1969), 509-512. English translation in Soviet Math. Doklady 10 (No. 3, 1969), 618-622. [Annotated scanned copy]

Crossrefs

Cf. A001035.

Programs

Mathematica

A001035 = DeleteCases[Import["https://oeis.org/A001035/b001035.txt", "Table"], b_ /; ! MatchQ[b, {_Integer, _Integer}] ][[All, 2]];
a[n_] := Binomial[n, 2] * A001035[[n - 1]];
Table[a[n], {n, 2, Length[A001035] + 1}] (* Jean-François Alcover, May 11 2019 *)

Formula

a(n) = binomial(n, 2) * A001035(n - 2). - Sean A. Irvine, Aug 24 2014

Extensions

More terms from Alois P. Heinz, Jun 02 2017