A080728 a(0) = 3; 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 member of the sequence if and only if a(n) == 2 mod 3".

3, 4, 6, 8, 11, 12, 14, 15, 17, 18, 19, 20, 23, 24, 26, 29, 30, 32, 35, 38, 41, 42, 43, 44, 47, 48, 50, 51, 52, 53, 56, 57, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 71, 74, 77, 78, 79, 80, 83, 84, 86, 89, 92, 95, 96, 97, 98, 101, 102, 104, 107, 110, 113, 116, 119, 122, 125, 128

Offset

0,1

Links

Table of n, a(n) for n=0..67.

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 (math.NT/0305308)

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

Formula

a(a(n)) = 3*n+8, n >= 0.

Prog

(PARI) {a=3; m=[3]; for(n=1, 68, print1(a, ", "); a=a+1; if(a%3==2&&a==n, qwqw=qwqw, if(m==[], while((a%3!=2&&a==n)||a%3==2, a++), if(m[1]==n, while(a%3!=2, a++); m=if(length(m)==1, [], vecextract(m, "2..")), if(a%3==2, a++))); m=concat(m, a)))}

Crossrefs

Cf. A079000, A080720, ...

Sequence in context: A325455 A069357 A337455 * A047414 A109402 A020901

Adjacent sequences: A080725 A080726 A080727 * A080729 A080730 A080731

Keyword

nonn,easy

Author

N. J. A. Sloane, Mar 08 2003

Extensions

More terms and PARI code from Klaus Brockhaus, Mar 09 2003

Status

approved