Sha256: 2d1096377d440c1ce77b6d58db9374d0450a4f61958bc24b6acde35705c4b49a
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Size: 803 Bytes
Versions: 5
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Stored size: 803 Bytes
Contents
# coding: utf-8
class Integer
def multiamicable?(m, a, b)
return false unless m != self and m < self and a.positive? and b.positive?
m.σ - m == a*self and σ - self == b*m
end
def amicable?(other)
n, m = [self, other].minmax
m.multiamicable?(n, 1, 1)
end
def augmented_amicable?(n)
m = self
[m.σ, n.σ].all?{|sigma| sigma == m + n - 1}
end
def betrothed?(m)
σ == m.σ and consecutive?(σ - m)
end
alias :quasi_amicable? :betrothed?
alias :reduced_amicable? :betrothed?
def breeder?(b)
a = self
x = (a.σ - a).fdiv(b)
abx = a + (b*x)
(abx == a.σ) and (abx == b.σ * (x + 1))
end
def unitary_amicable?(n)
[n + self, sum_of_unitary_divisors].all? do |other|
other == n.sum_of_unitary_divisors
end
end
end
Version data entries
5 entries across 5 versions & 1 rubygems