A216659 Number of n-digit 9th powers.

2, 0, 1, 0, 1, 1, 1, 2, 2, 3, 4, 5, 6, 8, 11, 13, 18, 22, 30, 37, 49, 63, 81, 105, 135, 175, 225, 292, 377, 486, 628, 811, 1048, 1353, 1748, 2257, 2916, 3766, 4863, 6281, 8113, 10477, 13533, 17478, 22573, 29155, 37656, 48633, 62812, 81126, 104777, 135326

Offset

1,1

Links

Alois P. Heinz, Table of n, a(n) for n = 1..1000

Example

a(1) = 2: 0, 1.
a(3) = 1: 512.
a(5) = 1: 19683.
a(9) = 2: 134217728, 387420489.
a(10) = 3: 1000000000, 2357947691, 5159780352.
a(11) = 4: 10604499373, 20661046784, 38443359375, 68719476736.

Maple

r:= proc(n, k) local b; b:= iroot(n, k); b+`if`(b^k<n, 1, 0) end:
a:= n-> r(10^n, 9) -r(10^(n-1), 9) +`if`(n=1, 1, 0):
seq(a(n), n=1..60);

Crossrefs

Column k=9 of A216653.

Sequence in context: A015879 A230000 A016242 * A321396 A141747 A239706

Adjacent sequences: A216656 A216657 A216658 * A216660 A216661 A216662

Keyword

nonn,base

Author

Alois P. Heinz, Sep 12 2012

Status

approved