1. Harmonic divisor numberIn mathematics, a harmonic divisor number, or Ore number (named after Øystein Ore who defined it in 1948), is a positive integer whose divisors have a harmonic mean that is an integer. The first few harmonic divisor numbers are 1, 6, 28, 140, 270, 496, 672, 1638, 2970, 6200, 8128, 8190. For example, the harmonic divisor number 6 has the four divisors 1, 2, 3, and 6. Their harmonic mean is an integer: The number 140 has divisors 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, and 140.
Read “Harmonic divisor number” on English Wikipedia
Read “調和数” on Japanese Wikipedia
Read “Harmonic divisor number” on DBpedia
Read “Harmonic divisor number” on English Wikipedia
Read “調和数” on Japanese Wikipedia
Read “Harmonic divisor number” on DBpedia
Discussions
Log in to talk about this word.