Here are outside websites on matters related to the N + k Queens Problem:
- http://liacs.leidenuniv.nl/~kosterswa/nqueens/: Walter Kosters' extensive bibliography on the n-queens problem and related problems.
- http://www.arxiv.org/abs/cs/0701049v2: Barnaby Martin's preprint showing the NP-completeness of a problem similar to the N+k Queens Problem.
- http://en.wikipedia.org/wiki/Alternating_sign_matrix: Take a N+k Queens (or Rooks) solution, replace the pawns with -1's, the queens (rooks) with 1's and the empty squares with 0's, and you get an alternating sign matrix. The Wikipedia article includes links to some interesting papers.
- http://www.amherst.edu/~nstarr/puzzle.html: Norton Starr's pages on tiling a "deficient" board with trominoes.
- http://www.maa.org/news/091508scimf.html: Mathematical Association of America Online article about a September 5, 2008 Science article that mentions my August 1 MathFest talk and describes the N+k Queens Problem.
- http://www.informatik.tu-freiberg.de/prof2/publikationen/ICAART2010_SDCP.pdf: Christian Posthoff and Bernd Steinbach use ternary vectors to solve SAT problems. The N+k Queens Problem is used as an example.
- http://file.scirp.org/pdf/OJDM_2016071414515019.pdf: "The Independence-Separation Problem on the 3-D Rook's Graph", by Paul Burchett, Open Journal of Discrete Mathematics, 2016, 6, 167-173.
- http://www.nnw.cz/doi/2017/NNW.2017.27.016.pdf: "Optimization of N+1 Queens Problem Using Discrete Neural Network", by M. Waqas and A.A. Bhatti, Neural Network World 27.3 (2017).
- https://medium.freecodecamp.org/how-to-solve-the-baby-lizards-problem-a-fun-variant-on-the-n-queens-problem-a6980f5e72a Blog post on solving the Baby Lizards problem, which is similar to the N+k Queens Problem.