139 citations
- Cerro Tololo Inter-American ObservatoryCL2 papers
- Naval Postgraduate SchoolUS2 papers
- Universidad Nacional Autónoma de MéxicoMX2 papers
- University of New MexicoUS2 papers
- Academia SinicaTW1 paper
- American Astronomical SocietyUS1 paper
- Astronomical Institute of the Slovak Academy of SciencesSK1 paper
- Astrophysique, Instrumentation et ModélisationFR1 paper
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4 papers · 1 filter
A special sequence and primorial numbers
Amit Kumar Basistha, Eugen J. Ionascu
In this paper, we study a class of functions defined recursively on the set of natural numbers in terms of the greatest common divisor algorithm of two numbers and requiring a mini…
Minimal Niven numbers
H. Fredricksen, E. J. Ionascu, F. Luca +1
Define a(k,q) to be the smallest positive multiple of k such that the sum of its digits in base q is equal to k. The asymptotic behavior, lower and upper bound estimates of a(k,q)…
Heron triangles with two fixed sides
Eugen J. Ionascu, Florian Luca, Pantelimon Stanica
In this paper, we study the function , which associates to every pair of positive integers and the number of positive integers such that the triangle of sides $…
A parametrization of equilateral triangles having integer coordinates
Eugen J. Ionascu
We study the existence of equilateral triangles of given side lengths and with integer coordinates in dimension three. We show that such a triangle exists if and only if their side…