This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A282618 #24 Jul 15 2025 08:23:37
%S A282618 0,0,2,6,26,108,492,2562,14790,98874,720614,5908394,52572682,
%T A282618 516141316,5422012074,61889630476,749456000504,9767057565198,
%U A282618 134007980469502,1958535740848524
%N A282618 Number of non-self-conjugate separable solutions of X + Y = 2Z (integer, disjoint triples from {1,2,3,...,3n}).
%C A282618 An inseparable solution is one in which "there is no j such that the first j of the triples are a partition of 1, ..., 3j" (see A202705).
%C A282618 A self-conjugate solution is one in which for every triple (a, b, c) in the partition there exists a "conjugate" triple (m-a, m-b, m-c) or (m-b, m-a, m-c) where m = 3n+1.
%C A282618 | separable | inseparable | either |
%C A282618 -------------------+-----------+-------------+---------+
%C A282618 self-conjugate | A282615 | A279197 | A282616 |
%C A282618 non-self-conjugate | A282618 | A282617 | A282619 |
%C A282618 either | A279199 | A202705 | A104429 |
%F A282618 a(n) = A282619(n) - A282617(n).
%F A282618 a(n) = A279199(n) - A282615(n).
%e A282618 For n = 3 the a(3) = 2 solutions are:
%e A282618 (5,9,7),(4,8,6),(1,3,2), and
%e A282618 (7,9,8),(2,6,4),(1,5,3).
%Y A282618 Cf. A104429, A202705, A279197, A279199, A282615, A282616, A282617, A282619.
%K A282618 nonn,more
%O A282618 1,3
%A A282618 _Peter Kagey_, Feb 19 2017
%E A282618 a(10)-a(16) from _Fausto A. C. Cariboni_, Feb 27 2017
%E A282618 a(17) from _Fausto A. C. Cariboni_, Mar 22 2017
%E A282618 a(18)-a(20) from _Martin Fuller_, Jul 15 2025