A375433 a(n) is the smallest number of parallel straight lines needed to intersect all points (k, a(k)) for k < n.

0, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15

Offset: 1

Author

Rémy Sigrist, Aug 15 2024

Keywords

• nonn

Comments

This sequence is a variant of A373811. The two sequences coincide over the first 22 terms.

Examples

			See illustration in Links section.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, Illustration for a(21) = 6
• Rémy Sigrist, C++ program

Crossrefs

Cf. A373811, A375465.

Formula

a(n) <= a(n+1) <= a(n) + 1.