cp's OEIS Frontend

A278338 Irregular triangle read by rows in which row n contains the first Carmichael number equal to m mod n where m is coprime to n, 0 <= m < n, ordered by m.

%I A278338 #9 Dec 12 2016 09:19:40
%S A278338 561,561,1105,2465,561,8911,561,46657,52633,1729,1105,2465,561,46657,
%T A278338 294409,29341,512461,1105,561,1024651,2821,8911,1729,1909001,2821,
%U A278338 162401,1105,2465,561,52633,46657,1729,2465,1729,10585,29341,1105,46657,1193221
%N A278338 Irregular triangle read by rows in which row n contains the first Carmichael number equal to m mod n where m is coprime to n, 0 <= m < n, ordered by m.
%C A278338 The n-th row contains phi(n) terms. Wright proves that this sequence exists for each coprime m and n.
%H A278338 Charles R Greathouse IV, <a href="/A278338/b278338.txt">Rows n = 1..179 of triangle, flattened</a>
%H A278338 Thomas Wright, <a href="https://arxiv.org/abs/1212.5850">Infinitely many Carmichael numbers in arithmetic progressions</a>, Bulletin of the London Mathematical Society 45:5 (2013), pp. 943-952.
%F A278338 a(n) is the least Carmichael number equal to A038566(n) mod A038567(n).
%e A278338 561 = 0 mod 1;
%e A278338 561 = 1 mod 2;
%e A278338 1105 = 1 mod 3, 2465 = 2 mod 3;
%e A278338 561 = 1 mod 4, 8911 = 3 mod 4;
%e A278338 561 = 1 mod 5, 46657 = 2 mod 5, 52633 = 3 mod 5, 1729 = 4 mod 5;
%e A278338 1105 = 1 mod 6, 2465 = 5 mod 6;
%Y A278338 Cf. A002997, A038566, A038567.
%K A278338 nonn,tabf
%O A278338 1,1
%A A278338 _Charles R Greathouse IV_, Nov 18 2016