A023996 Triangle of numbers T(n,k), where T(n,k) is the number of sets S = {a_1, a_2, ..., a_k}, with 1 < a_i < a_j <= n such that no a_j divides the product of all the others.

1, 1, 1, 1, 2, 1, 1, 3, 2, 1, 4, 5, 2, 1, 5, 7, 3, 1, 6, 12, 10, 3, 1, 7, 16, 15, 5, 1, 8, 22, 24, 9, 1, 9, 28, 34, 14, 1, 10, 37, 62, 48, 14, 1, 11, 43, 74, 58, 17, 1, 12, 54, 117, 132, 75, 17, 1, 13, 64, 151, 182, 108, 25, 1, 14, 75, 184, 224, 132, 30, 1, 15, 86

Offset: 0

Author

Lionel Levine (levine(AT)ultranet.com)

Keywords

• tabf
• nonn

Examples

			From _Sean A. Irvine_, Jun 17 2019: (Start)
  1;
  1,  1;
  1,  2,  1;
  1,  3,  2;
  1,  4,  5,  2;
  1,  5,  7,  3;
  1,  6, 12, 10,  3;
  ... (End)
		

Links

• Sean A. Irvine, Table of n, a(n) for n = 0..586 (rows 0..55 flattened)
• Sean A. Irvine, Java program (github)

Crossrefs

Cf. A023995.