cp's OEIS Frontend

A330403 Lexicographically earliest sequence of distinct positive terms with an associate sequence t such that t(0) = 0, and for any n > 0, at least one of t(n-1) - a(n) or t(n-1) + a(n) is a square; in case t(n-1) - a(n) is a square, set t(n) = t(n-1) - a(n), otherwise set t(n) = t(n-1) + a(n).

%I A330403 #12 Dec 16 2019 02:19:21
%S A330403 1,3,4,9,5,12,7,8,15,16,25,11,13,24,21,32,20,33,40,27,28,17,19,36,39,
%T A330403 56,45,35,48,49,64,55,72,63,23,57,60,77,65,84,44,52,29,31,68,37,80,41,
%U A330403 76,99,81,95,51,69,87,105,123,43,88,47,92,141,96,129,111,93
%N A330403 Lexicographically earliest sequence of distinct positive terms with an associate sequence t such that t(0) = 0, and for any n > 0, at least one of t(n-1) - a(n) or t(n-1) + a(n) is a square; in case t(n-1) - a(n) is a square, set t(n) = t(n-1) - a(n), otherwise set t(n) = t(n-1) + a(n).
%C A330403 This sequence is a variant of A330385.
%H A330403 Rémy Sigrist, <a href="/A330403/b330403.txt">Table of n, a(n) for n = 1..10000</a>
%H A330403 Rémy Sigrist, <a href="/A330403/a330403.gp.txt">PARI program for A330403</a>
%e A330403 The first terms, alongside t(n), are:
%e A330403   n   a(n)  t(n)
%e A330403   --  ----  ----
%e A330403    0  N/A      0
%e A330403    1     1     1
%e A330403    2     3     4
%e A330403    3     4     0
%e A330403    4     9     9
%e A330403    5     5     4
%e A330403    6    12    16
%e A330403    7     7     9
%e A330403    8     8     1
%e A330403    9    15    16
%e A330403   10    16     0
%e A330403   11    25    25
%e A330403   12    11    36
%o A330403 (PARI) See Links section.
%Y A330403 See A330401 for similar sequences.
%Y A330403 Cf. A330385, A330422 (running totals).
%K A330403 nonn
%O A330403 1,2
%A A330403 _Rémy Sigrist_, Dec 13 2019