A098232 Largest power of 2 <= 3^n.

1, 2, 8, 16, 64, 128, 512, 2048, 4096, 16384, 32768, 131072, 524288, 1048576, 4194304, 8388608, 33554432, 67108864, 268435456, 1073741824, 2147483648, 8589934592, 17179869184, 68719476736, 274877906944, 549755813888, 2199023255552, 4398046511104, 17592186044416

Offset: 0

Author

Henry Bottomley, Oct 25 2004

Keywords

• easy
• nonn

Examples

			a(4)=64 since 3^4=81 and 64 <= 81 < 128.
		

Crossrefs

Cf. A000079, A000244, A020857, A022921, A056576, A056577.

Programs

Maple

A098232:=n->2^floor(n*log[2](3)): seq(A098232(n), n=0..30); # Wesley Ivan Hurt, Mar 12 2015

PARI

a(n) = 2^logint(3^n, 2); \\ Michel Marcus, Sep 06 2022

Formula

a(n) = 2^floor(n*log_2(3)) = A000079(A056576(n)) = A000244(n)-A056577(n).