A245356 Number of numbers whose base-4/3 expansion (see A024631) has n digits.

4, 4, 4, 4, 8, 8, 12, 16, 20, 28, 36, 48, 64, 88, 116, 156, 208, 276, 368, 492, 656, 872, 1164, 1552, 2068, 2760, 3680, 4904, 6540, 8720, 11628, 15504, 20672, 27560, 36748, 48996, 65328, 87104, 116140, 154852, 206472, 275296, 367060, 489412, 652552, 870068

Offset: 1

Author

Hailey R. Olafson, Jul 18 2014

Keywords

• nonn
• base

Examples

			a(3) = 4 because 320, 321, 322, and 323 are the base-4/3 expansions for the numbers 9, 10, 11, and 12 respectively and these are the only numbers with 3 digits.
		

Crossrefs

Cf. A072493, A024631, A081848.

Programs

Sage

A=[1]
for i in [1..60]:
    A.append(ceil(((4-3)/3)*sum(A)))
[4*x for x in A]

Formula

a(n) = 4*A072493(n).