cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A246417 Homomorphic inverse images of elementary h-ary relations.

Original entry on oeis.org

0, 0, 1, 7, 36, 171, 813, 4012, 25931, 342263, 6498746, 116477549, 1839530421, 26071946330, 339710531761, 4165394873379, 50578180795388, 717354862704287, 15348610400624113, 466529833772501084, 15332096138370552335
Offset: 1

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Author

Sean A. Irvine, Aug 25 2014

Keywords

Comments

Corresponds to r_6(k) in the Rosenberg paper.

References

  • 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.

Crossrefs

Cf. A002826.

Formula

a(n) = Sum_{h^m <= k, h >= 3, m >= 1} (((-1)^h / (m! * (h!)^m)) * Sum_{L=1..h^m} (-1)^L * binomial(h^m, L) * L^n). - Sean A. Irvine, Aug 25 2014