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A279543 a(n) = a(n-1) + 3^n * a(n-2) with a(0) = 1 and a(1) = 1. 3

%I #29 Jan 01 2017 02:44:21

%S 1,1,10,37,847,9838,627301,22143007,4137864868,439978671649,

%T 244776761262181,78185678507867584,130162592460442600405,

%U 124783388108159412726037,622688428086038843429228482,1791127919536971393223950620041

%N a(n) = a(n-1) + 3^n * a(n-2) with a(0) = 1 and a(1) = 1.

%C The Rogers-Ramanujan continued fraction is defined by R(q) = q^(1/5)/(1+q/(1+q^2/(1+q^3/(1+ ... )))). The limit of a(n)/A015460(n+2) is 3^(-1/5) * R(3).

%H Seiichi Manyama, <a href="/A279543/b279543.txt">Table of n, a(n) for n = 0..90</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Rogers-RamanujanContinuedFraction.html">Rogers-Ramanujan Continued Fraction</a>

%e 1/1 = a(0)/A015460(2).

%e 1/(1+3/1) = 1/4 = a(1)/A015460(3).

%e 1/(1+3/(1+3^2/1)) = 10/13 = a(2)/A015460(4).

%e 1/(1+3/(1+3^2/(1+3^3/1))) = 37/121 = a(3)/A015460(5).

%t RecurrenceTable[{a[n] == a[n - 1] + 3^n*a[n - 2], a[0] == 1, a[1] == 1}, a, {n, 15}] (* _Michael De Vlieger_, Dec 31 2016 *)

%Y Cf. A015460, A128915.

%Y Cf. similar sequences with the recurrence a(n-1) + q^n * a(n-2) for n>1, a(0)=1 and a(1)=1: A280294 (q=2), this sequence (q=3), A280340 (q=10).

%K nonn

%O 0,3

%A _Seiichi Manyama_, Dec 31 2016

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Last modified April 25 04:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)