A064631 a(n) = ceiling(log_2(A064630(n))).

2, 3, 3, 5, 5, 4, 7, 7, 8, 10, 11, 12, 13, 14, 15, 16, 16, 16, 18, 18, 20, 22, 21, 23, 25, 25, 24, 28, 27, 29, 31, 32, 33, 34, 35, 36, 37, 37, 39, 40, 39, 42, 42, 44, 44, 46, 46, 46, 49, 50, 51, 51, 51, 54, 55, 55, 57, 57, 59, 60, 60, 61, 63, 64, 64, 66, 60, 62, 67, 70, 69, 72

Offset: 1

Author

Labos Elemer, Oct 01 2001

Keywords

• nonn

Comments

In A064630, using a greedy algorithm we write 4^n = x*3^n+y*2^n+z*1^n and A064630(n) = x+y+z. This sequence is a measure of the "length" or complexity of those solutions.

Crossrefs

Cf. A002379, A002380, A060692, A064628, A064629, A064630, A029837.

Formula

a(n) = A029837(A064630(n)) = ceiling(log_2(A064630(n))).

Extensions

Initial terms corrected and entry revised by Sean A. Irvine, Jul 18 2023