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Given the infinite continued fraction (1+i)+((1+i)/(1+i)+((1+i)/((1+i)+...)))), where i is the square root of (-1), this is the numerator of the real part of the convergents.
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%I #4 Feb 24 2021 08:36:57

%S 1,3,8,6,23,199,576,208,4809,4633,40168,29022,335501,33435,62272,

%T 506164,23405457,67643027,195491976,47081858,39825101,4718963799,

%U 13638058496,4926840072,5424316981,329207907547,951428510952,23704133014

%N Given the infinite continued fraction (1+i)+((1+i)/(1+i)+((1+i)/((1+i)+...)))), where i is the square root of (-1), this is the numerator of the real part of the convergents.

%C The sequence of complex numbers (which this sequence is part of) appears to converge to

%C 1.529085513635746125160990523790225210619365... + i*0.74293413587832283909143193794726628109624299200...

%C Using Plouffe's Inverter yields:

%C Roots of polynomials of 5th degree (coeffs: -9..9) 1529085513635746 = 1+1*x-4*x^2-6*x^3+4*x^4+4*x^5

%C Roots of polynomials of 5th degree (coeffs: -9..9) 7429341358783228 = 1+5*x+4*x^2-2*x^3-4*x^4-4*x^5

%H Simon Plouffe, <a href="http://wayback.cecm.sfu.ca/projects/ISC/ISCmain.html">Plouffe's Inverter </a>

%t Table[ Re[ Numerator[ FromContinuedFraction[ Table[1 + I, {n}]]]], {n, 30}]

%Y Cf. A091806, A091807, A091808, A091809, A093726, A093727.

%K frac,nonn

%O 1,2

%A _Robert G. Wilson v_, Mar 11 2004