cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A002357 Denominators of convergents to cube root of 5.

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%I A002357 M2692 N1078 #24 Jul 04 2024 20:06:56
%S A002357 1,1,3,7,31,100,331,431,2486,2917,5403,24529,250693,4286310,4537003,
%T A002357 67804352,72341355,140145707,427797039119,427937184826,855734223945,
%U A002357 1283671408771,2139405632716,3423077041487,5562482674203,14548042389893
%N A002357 Denominators of convergents to cube root of 5.
%D A002357 D. H. Lehmer, Guide to Tables in the Theory of Numbers. Bulletin No. 105, National Research Council, Washington, DC, 1941, p. 67.
%D A002357 P. Seeling, Verwandlung der irrationalen Groesse ... in einen Kettenbruch, Archiv. Math. Phys., 46 (1866), 80-120.
%D A002357 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002357 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%e A002357 1 + 1/(1 + 1/(2 + 1/(2 + 1/4))) = 53/31 so a(5) = 31.
%o A002357 (PARI) a(n)=if(n<1,0,contfracpnqn(contfrac(5^(1/3),n))[2,1])
%Y A002357 Cf. A002358 (numerators), A005481.
%K A002357 nonn,frac
%O A002357 0,3
%A A002357 _N. J. A. Sloane_
%E A002357 More terms from _Herman P. Robinson_
%E A002357 Offset changed by _Andrew Howroyd_, Jul 04 2024