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A080720 a(0) = 5; 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) is a multiple of 3". 7

%I #10 Mar 30 2012 17:27:40

%S 5,7,8,10,11,12,13,15,18,19,21,24,27,30,31,33,34,35,36,39,40,42,43,44,

%T 45,46,47,48,49,50,51,54,55,57,60,63,66,67,68,69,72,73,75,78,81,84,87,

%U 90,93,96,99,102,103,104,105,108,109,111,112,113,114,115,116,117,118,119

%N a(0) = 5; 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) is a multiple of 3".

%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.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="http://arXiv.org/abs/math.NT/0305308">Numerical analogues of Aronson's sequence</a> (math.NT/0305308)

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

%F a(a(n)) = 3*(n+4).

%o (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))}

%Y Cf. A079000, A003605, A079253, A080711, A080710.

%K nonn,easy

%O 0,1

%A _N. J. A. Sloane_, Mar 05 2003

%E More terms and PARI code from _Klaus Brockhaus_, Mar 07 2003

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)