

A080720


a(0) = 5; for n>0, a(n) is taken to be the smallest positive integer greater than a(n1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is a multiple of 3".


7



5, 7, 8, 10, 11, 12, 13, 15, 18, 19, 21, 24, 27, 30, 31, 33, 34, 35, 36, 39, 40, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 54, 55, 57, 60, 63, 66, 67, 68, 69, 72, 73, 75, 78, 81, 84, 87, 90, 93, 96, 99, 102, 103, 104, 105, 108, 109, 111, 112, 113, 114, 115, 116, 117, 118, 119
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OFFSET

0,1


LINKS

Table of n, a(n) for n=0..65.
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+4).


PROG

(PARI) {a=5; m=[5]; for(n=1, 66, print1(a, ", "); a=a+1; if(m[1]==n, while(a%3>0, a++); m=if(length(m)==1, [], vecextract(m, "2..")), if(a%3==0, a++)); m=concat(m, a))}


CROSSREFS

Cf. A079000, A003605, A079253, A080711, A080710.
Sequence in context: A309277 A180241 A047479 * A189034 A112250 A192067
Adjacent sequences: A080717 A080718 A080719 * A080721 A080722 A080723


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane, Mar 05 2003


EXTENSIONS

More terms and PARI code from Klaus Brockhaus, Mar 07 2003


STATUS

approved



