This article covers the number 290. For the year, see 290.

290 (two hundred [and] ninety) is the natural number following 289 and preceding 291.

In mathematics

The product of three primes, 290 is a sphenic number, and the sum of four consecutive primes (67 + 71 + 73 + 79). The sum of the squares of the divisors of 17 is 290.

Not only is it a nontotient and a noncototient, it is also an untouchable number.

290 is the 16th member of the Mian–Chowla sequence; it can not be obtained as the sum of any two previous terms in the sequence.[1]

See also the Bhargava–Hanke 290 theorem.

References

  1. ^ "Sloane's A005282 : Mian-Chowla sequence". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
Allikas: https://en.wikipedia.org/wiki/290_(number)
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