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A309445 Coefficients in 7-adic expansion of 2^(1/5). 11
4, 6, 1, 3, 6, 4, 3, 5, 4, 6, 5, 4, 0, 0, 6, 4, 3, 4, 5, 6, 2, 2, 2, 0, 6, 5, 5, 0, 3, 1, 1, 4, 0, 4, 6, 2, 0, 6, 0, 3, 6, 3, 2, 5, 4, 6, 4, 0, 5, 5, 2, 1, 4, 3, 4, 1, 0, 1, 1, 6, 0, 4, 1, 6, 0, 4, 5, 1, 1, 6, 2, 5, 2, 3, 0, 6, 1, 3, 6, 4, 0, 6, 2, 6, 4, 2, 0, 1, 6, 3, 6, 5, 1, 2, 4, 3, 3, 0, 4, 6, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Robert Israel, Table of n, a(n) for n = 0..10000

MAPLE

op([1, 3], padic:-rootp(x^5-2, 7, 101)); # Robert Israel, Aug 04 2019

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 A309445(n)

  A([-2, 0, 0, 0, 0, 1], 4, 7, n)

end

p A309445(100)

(PARI) Vecrev(digits(truncate((2+O(7^100))^(1/5)), 7))

CROSSREFS

Cf. A309450.

Digits of p-adic integers:

A290566 (5-adic, 2^(1/3));

A309446 (7-adic, 3^(1/5));

A309447 (7-adic, 4^(1/5));

A309448 (7-adic, 5^(1/5));

A309449 (7-adic, 6^(1/5)).

Sequence in context: A154478 A255695 A246489 * A051261 A247621 A245275

Adjacent sequences:  A309442 A309443 A309444 * A309446 A309447 A309448

KEYWORD

nonn,base

AUTHOR

Seiichi Manyama, Aug 03 2019

STATUS

approved

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Last modified April 17 23:03 EDT 2021. Contains 343071 sequences. (Running on oeis4.)