A385970 a(n) is the minimum number of powers needed to obtain the n-th term of sequence A385969.

1, 2, 1, 2, 2, 2, 3, 3, 3, 2, 3, 3, 2, 3, 3, 2, 4, 3, 4, 4, 1, 2, 3, 3, 2, 3, 3, 3, 2, 4, 4, 3, 4, 3, 2, 3, 4, 4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 4, 3, 2, 4, 3, 3, 4, 3, 4, 4, 5, 4, 4, 4, 4, 3, 3, 5, 5, 4, 3, 4, 4, 4, 4, 3, 4, 5, 2, 3, 4, 4, 5, 4, 4, 5, 4, 4, 3, 4, 5, 4, 2, 4, 3, 5, 4, 5

Offset: 1

Author

Alberto Zanoni, Jul 14 2025

Keywords

• nonn

Comments

The sequence is unbounded (conjectured).

Examples

			a(1) = 1, as  4 = 2^2
a(2) = 2, as 17 = 2^3 + 3^2
a(3) = 1, as 27 = 3^3
a(4) = 2, as 31 = 2^2 + 3^3
a(7) = 3, as 59 = 2^4 + 3^3 + 4^2
		

Crossrefs

Cf. A385969, A385232, A385233.