A281196 Number of n such that A247600(n) = 5.

9, 10, 11, 12, 13, 14, 19, 20, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39, 41

Offset: 1

Author

Seiichi Manyama, Jan 17 2017

Keywords

• nonn
• fini
• full

Comments

Conjecture: This sequence has just 22 terms shown.

Sequence is finite and complete. Since pi(x) < 1.25506*x/log(x), it follows that for x > 106, pi(5*x) < x + 5. - Chai Wah Wu, May 01 2018, May 14 2020.

Examples

			9 is a term since pi(5*9) = 14 = 9 + 5, and pi(m*9) = 9 + m for no m < 5.
		

Crossrefs

Cf. A000720, A247600, A281197.

Formula

pi(5*a(n)) = a(n) + 5.