A216655 Number of n-digit 5th powers.

2, 1, 1, 3, 3, 6, 10, 14, 24, 36, 59, 93, 147, 232, 369, 585, 927, 1470, 2328, 3690, 5849, 9270, 14692, 23285, 36904, 58490, 92699, 146919, 232850, 369042, 584894, 926993, 1469185, 2328502, 3690426, 5848932, 9269933, 14691853, 23285017, 36904265, 58489320

Offset

1,1

Links

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

Example

a(1) = 2: 0, 1.
a(2) = 1: 32.
a(3) = 1: 243.
a(4) = 3: 1024, 3125, 7776.
a(5) = 3: 16807, 32768, 59049.
a(6) = 6: 100000, 161051, 248832, 371293, 537824, 759375.
a(7) = 10: 1048576, 1419857, 1889568, 2476099, 3200000, 4084101, 5153632, 6436343, 7962624, 9765625.

Maple

r:= proc(n, k) local b; b:= iroot(n, k); b+`if`(b^k<n, 1, 0) end:
a:= n-> r(10^n, 5) -r(10^(n-1), 5) +`if`(n=1, 1, 0):
seq(a(n), n=1..50);

Crossrefs

Column k=5 of A216653.

Sequence in context: A184834 A276777 A219876 * A242884 A197219 A300508

Adjacent sequences: A216652 A216653 A216654 * A216656 A216657 A216658

Keyword

nonn,base

Author

Alois P. Heinz, Sep 12 2012

Status

approved