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.

A074894 Full list of counterexamples for the k=3 version of the malicious apprentice problem.

Original entry on oeis.org

3, 6, 27, 486
Offset: 1

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Author

N. J. A. Sloane, based on email from R. K. Guy, Oct 30 2008

Keywords

Comments

This is the problem of the farmer's helper who, when asked to weigh n bags of grain, does so k at a time and reports the resulting binomial(n,k) combined weights with no indication of the k-tuples that produced them. The problem: is can the weights of the bags be recovered?
For k=3 the answer is Yes unless n is one of the four terms of this sequence. For k=2 see A057716.
The old entry with this sequence number was a duplicate of A030109.
The following references also apply to the general case of the problem.

Examples

			For n=27 Boman and Linusson give five examples of which the simplest is {-4,-1^{10},2^{16}} and its negative, where exponents denote repetitions. For n=486 Boman and Linusson give {-7,-4^{56},-1^{231},2^{176},5^{22}} and its negative.
		

References

  • W. W. Rouse Ball, A Short Account of the History of Mathematics.
  • E. Bolker, The finite Radon transform, Contemp. Math., 63 (1987) 27-50.
  • R. K. Guy, Unsolved Problems in Number Theory, C5.
  • Ross A. Honsberger, A gem from combinatorics, Bull. ICA, 1 (1991) 56-58.
  • B. Liu and X. Zhang, On harmonious labelings of graphs, Ars Combin., 36 (1993) 315-326.
  • J. Ossowski, On a problem of Galvin, Congressus Numerantium, 96 (1993) 65-74.
  • P. Winkler, Mathematical Mind-Benders, Peters, Wellesley, MA, 2007; see p. 27.

Crossrefs

See A057716 for the case k=2.