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A290566
Coefficients in 5-adic expansion of 2^(1/3).
17
3, 0, 2, 2, 3, 1, 4, 0, 2, 3, 0, 0, 4, 0, 4, 4, 3, 1, 1, 2, 0, 0, 2, 4, 0, 0, 2, 1, 4, 2, 2, 4, 0, 4, 2, 3, 1, 2, 3, 0, 0, 2, 0, 3, 4, 4, 2, 3, 2, 0, 4, 1, 2, 2, 3, 3, 0, 4, 2, 2, 3, 4, 4, 3, 4, 0, 2, 1, 2, 3, 4, 4, 2, 3, 3, 0, 3, 4, 1, 3, 1, 0, 2, 2, 1, 4, 4, 1
OFFSET
0,1
LINKS
PROG
(Ruby)
require 'OpenSSL'
def f_a(ary, a)
(0..ary.size - 1).inject(0){|s, i| s + ary[i] * a ** i}
end
def df(ary)
(1..ary.size - 1).map{|i| i * ary[i]}
end
def A(c_ary, k, m, n)
x = OpenSSL::BN.new((-f_a(df(c_ary), k)).to_s).mod_inverse(m).to_i % m
f_ary = c_ary.map{|i| x * i}
f_ary[1] += 1
d_ary = []
ary = [0]
a, mod = k, m
(n + 1).times{|i|
b = a % mod
d_ary << (b - ary[-1]) / m ** i
ary << b
a = f_a(f_ary, b)
mod *= m
}
d_ary
end
def A290566(n)
A([-2, 0, 0, 1], 3, 5, n)
end
p A290566(100)
(PARI) Vecrev( digits( truncate( (2+O(5^100))^(1/3) ), 5) ) \\ Joerg Arndt, Aug 06 2017
CROSSREFS
Sequence in context: A004587 A104609 A326395 * A285006 A369747 A300722
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 06 2017
STATUS
approved