A018068 Powers of fourth root of 8 rounded up.

1, 2, 3, 5, 8, 14, 23, 39, 64, 108, 182, 305, 512, 862, 1449, 2436, 4096, 6889, 11586, 19484, 32768, 55109, 92682, 155872, 262144, 440872, 741456, 1246975, 2097152, 3526976, 5931642, 9975793, 16777216

Offset

0,2

Links

Robert Israel, Table of n, a(n) for n = 0..4424

Formula

a(n) = ceiling(8^(n/4)). - Michel Marcus, Dec 28 2020

Maple

seq(ceil(8^(n/4)), n=0..40); # Robert Israel, Dec 28 2020

Prog

(PARI) a(n) = n*=3; if(n%2, sqrtnint(1<<n, 4)+1, n%4, sqrtint(1<<(n/2))+1, 1<<(n/4)); \\ Kevin Ryde, Dec 29 2020

Crossrefs

Cf. A001018 (powers of 8).

Sequence in context: A094926 A225391 A078843 * A120400 A217283 A000621

Adjacent sequences: A018065 A018066 A018067 * A018069 A018070 A018071

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved