A020340 Least square base n doublet (written in base 10).

36, 4, 378225, 7056, 14393520729, 16, 9, 557904400, 1322314049613223140496, 36, 613401598811409576100, 321418490709904, 837225, 16, 7535664872989640713426833504575377836025, 36, 16900, 100, 7112889

Offset: 2

Author

David W. Wilson

Keywords

• base
• nonn

Comments

In Bridy et al. it is shown how to construct infinitely many examples for any given base n >= 2. - Jeffrey Shallit, Jun 14 2021

References

• Andrew Bridy, Robert J. Lemke Oliver, Arlo Shallit, and Jeffrey Shallit, The Generalized Nagell-Ljunggren Problem: Powers with Repetitive Representations, Experimental Math, 28 (2019), 428-439.
• David Wells, "The Penguin Dictionary of Curious and Interesting Numbers", Revised Edition 1997, p. 189.

Links

• Andrew Bridy, Robert J. Lemke Oliver, Arlo Shallit, and Jeffrey Shallit, The Generalized Nagell-Ljunggren Problem: Powers with Repetitive Representations, preprint arXiv:1707.03894 [math.NT], July 14 2017.
• A. Ottens, The arithmetic-digits-squares-three.digits problem

Crossrefs

Cf. A020339, A054214, A054215, A054216, A030465, A030466, A030467.