A080722 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, 1, 3, 4, 7, 8, 9, 10, 13, 16, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 31, 34, 37, 40, 43, 46, 49, 52, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 85, 88, 91, 94, 97, 100, 103, 106, 109, 112, 115, 118, 121

Offset

0,3

Links

Table of n, a(n) for n=0..68.

B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, J. Integer Seqs., Vol. 6 (2003), #03.2.2.

B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, arXiv:math/0305308 [math.NT], 2003.

Hsien-Kuei Hwang, Svante Janson, and Tsung-Hsi Tsai, Exact and asymptotic solutions of the recurrence f(n) = f(floor(n/2)) + f(ceiling(n/2)) + g(n): theory and applications, preprint, 2016.

Hsien-Kuei Hwang, Svante Janson, Tsung-Hsi Tsai, Exact and Asymptotic Solutions of a Divide-and-Conquer Recurrence Dividing at Half: Theory and Applications, ACM Transactions on Algorithms 13:4 (2017), #47.

Index entries for sequences of the a(a(n)) = 2n family

Formula

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

Prog

(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

Crossrefs

Cf. A079000, A080720.

Sequence in context: A057811 A284489 A026343 * A092754 A061094 A100991

Adjacent sequences: A080719 A080720 A080721 * A080723 A080724 A080725

Keyword

nonn,easy

Author

N. J. A. Sloane, Mar 08 2003

Extensions

More terms from Klaus Brockhaus, Mar 08 2003

Status

approved