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.

561, 561, 1105, 2465, 561, 8911, 561, 46657, 52633, 1729, 1105, 2465, 561, 46657, 294409, 29341, 512461, 1105, 561, 1024651, 2821, 8911, 1729, 1909001, 2821, 162401, 1105, 2465, 561, 52633, 46657, 1729, 2465, 1729, 10585, 29341, 1105, 46657, 1193221

Offset: 1

Author

Charles R Greathouse IV, Nov 18 2016

Keywords

• nonn
• tabf

Comments

The n-th row contains phi(n) terms. Wright proves that this sequence exists for each coprime m and n.

Examples

			561 = 0 mod 1;
561 = 1 mod 2;
1105 = 1 mod 3, 2465 = 2 mod 3;
561 = 1 mod 4, 8911 = 3 mod 4;
561 = 1 mod 5, 46657 = 2 mod 5, 52633 = 3 mod 5, 1729 = 4 mod 5;
1105 = 1 mod 6, 2465 = 5 mod 6;
		

Links

• Charles R Greathouse IV, Rows n = 1..179 of triangle, flattened
• Thomas Wright, Infinitely many Carmichael numbers in arithmetic progressions, Bulletin of the London Mathematical Society 45:5 (2013), pp. 943-952.

Crossrefs

Cf. A002997, A038566, A038567.

Formula

a(n) is the least Carmichael number equal to A038566(n) mod A038567(n).