Sparsely totient number
From Wikipedia, the free encyclopedia
In mathematics, a sparsely totient number is a certain kind of even natural number. A natural number, n, is sparsely totient if for all m > n,
- φ(m)>φ(n),
where φ is Euler's totient function. The first few sparsely totient numbers are:
2, 6, 12, 18, 30, 42, 60, 66, 90, 120, 126, 150, 210, 240, 270, 330, 420, 462, 510, 630 (sequence A036913 in OEIS).
[edit] References
- Roger C. Baker & Glyn Harman, "Sparsely totient numbers," Annales de la faculte des sciences de Toulouse Ser. 6 5 no. 2 (1996): 183 - 190
- D. W. Masser & P. Shiu, "On sparsely totient numbers," Pacific J. Math. 121, no. 2 (1986): 407 - 426.
