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A309930 Decimal expansion of the constant whose continued fraction representation is the cubes [0; 1, 8, 27, 64, ...], A000578.

%I A309930 #45 Jun 27 2025 16:28:05
%S A309930 8,8,9,3,4,4,0,0,0,0,3,2,7,6,2,6,9,3,6,0,5,4,9,4,7,0,6,3,2,1,2,2,1,9,
%T A309930 8,1,0,3,5,4,2,9,2,0,8,8,6,3,6,8,0,9,5,4,5,4,8,8,8,0,9,1,4,4,4,3,0,9,
%U A309930 6,7,6,4,1,7,6,8,1,4,9,8,0,5,6,1,8,3,4
%N A309930 Decimal expansion of the constant whose continued fraction representation is the cubes [0; 1, 8, 27, 64, ...], A000578.
%e A309930 0.8893440000327626936054947063212219810354292088...
%t A309930 N[FromContinuedFraction[Table[k^3, {k, 0, 1000}]], 120] (* _Vaclav Kotesovec_, Nov 20 2019 *)
%o A309930 (Python)
%o A309930 import decimal
%o A309930 from decimal import Decimal as D
%o A309930 def constant_from_cofr(clist):
%o A309930     hn0, kn0 = 0, 1
%o A309930     hn1, kn1 = 1, 0
%o A309930     for n in clist:
%o A309930         hn2 = (n * hn1) + hn0
%o A309930         kn2 = (n * kn1) + kn0
%o A309930         hn0, kn0 = hn1, kn1
%o A309930         hn1, kn1 = hn2, kn2
%o A309930     return D(hn2)/D(kn2)
%o A309930 if __name__ == "__main__":
%o A309930     prec = 200
%o A309930     decimal.getcontext().prec = prec
%o A309930     glist = [x**3 for x in range(500)]
%o A309930     print(', '.join(str(x) for x in str(constant_from_cofr(glist))[2:]))
%o A309930 (PARI) dec_exp(v)= w=contfracpnqn(v); w[1, 1]/w[2, 1]+0.
%o A309930 dec_exp(vector(2000, i, (i-1)^3)) \\ _Michel Marcus_, Nov 19 2019; after A073824
%Y A309930 Cf. A000578, A052119, A073824.
%K A309930 cons,nonn
%O A309930 0,1
%A A309930 _Daniel Hoyt_, Nov 11 2019