login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(0) = 0; for n > 0, a(n) is taken to be the smallest positive integer greater than a(n-1) which is consistent with the condition "n is a term of the sequence if and only if a(n) == 1 (mod 3)".
0

%I #25 Jul 15 2022 05:06:32

%S 0,1,3,4,7,8,9,10,13,16,19,20,21,22,23,24,25,26,27,28,31,34,37,40,43,

%T 46,49,52,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,

%U 75,76,77,78,79,80,81,82,85,88,91,94,97,100,103,106,109,112,115,118,121

%N a(0) = 0; for n > 0, a(n) is taken to be the smallest positive integer greater than a(n-1) which is consistent with the condition "n is a term of the sequence if and only if a(n) == 1 (mod 3)".

%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL6/Cloitre/cloitre2.html">Numerical analogues of Aronson's sequence</a>, J. Integer Seqs., Vol. 6 (2003), #03.2.2.

%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="https://arxiv.org/abs/math/0305308">Numerical analogues of Aronson's sequence</a>, arXiv:math/0305308 [math.NT], 2003.

%H Hsien-Kuei Hwang, Svante Janson, and Tsung-Hsi Tsai, <a href="http://140.109.74.92/hk/wp-content/files/2016/12/aat-hhrr-1.pdf">Exact and asymptotic solutions of the recurrence f(n) = f(floor(n/2)) + f(ceiling(n/2)) + g(n): theory and applications</a>, preprint, 2016.

%H Hsien-Kuei Hwang, Svante Janson, Tsung-Hsi Tsai, <a href="http://doi.org/10.1145/3127585">Exact and Asymptotic Solutions of a Divide-and-Conquer Recurrence Dividing at Half: Theory and Applications</a>, ACM Transactions on Algorithms 13:4 (2017), #47.

%H <a href="/index/Aa#aan">Index entries for sequences of the a(a(n)) = 2n family</a>

%F a(a(n)) = 3*n-2, n >= 2.

%o (PARI) {a=0; m=[]; for(n=1,70,print1(a,","); a=a+1; if(a%3==1&&a==n,qwqw=qwqw,if(m==[], while(a%3!=1&&a==n,a++),if(m[1]==n, while(a%3!=1,a++); m=if(length(m)==1,[],vecextract(m,"2..")),if(a%3==1,a++))); m=concat(m,a)))} \\ _Klaus Brockhaus_, Mar 08 2003

%Y Cf. A079000, A080720.

%K nonn,easy

%O 0,3

%A _N. J. A. Sloane_, Mar 08 2003

%E More terms from _Klaus Brockhaus_, Mar 08 2003