A335282 - OEIS

%I #11 Jun 02 2020 14:10:15

%S 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,26,27,28,

%T 29,30,31,32,33,34,35,36,37,38,39,40,41,42,46,47,48,49,50,51,52,53,54,

%U 55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72

%N Lexicographically earliest strictly increasing sequence of positive integers whose Recamán transform has only distinct values.

%C The Recamán transform of a sequence {b(n), n>0} is the sequence {r(n), n>=0} defined as follows: r(0) = 0; for n > 0, r(n) = r(n-1) - b(n) if nonnegative and not already in the sequence, otherwise r(n) = r(n-1) + b(n).

%C This sequence has large runs of consecutive terms.

%C The Recamán transform of this sequence, say r, first differ from A064388 for n = 123: r(123) = 19 whereas A064388(123) = 300.

%H Rémy Sigrist, <a href="/A335282/b335282.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Rea#Recaman">Index entries for sequences related to Recamán's sequence</a>

%o (PARI) { rr = 2^r=0; for (v=1, 72, forstep (s=-1, +1, 2, if (r+s*v>=0 && !bittest(rr, r+s*v), rr += 2^r+=s*v; print1 (v ", "); break))) }

%Y Cf. A005132, A064388.

%K nonn

%O 1,2

%A _Rémy Sigrist_, May 30 2020