A062941 Number of n-digit cubes (0 is included as a single-digit number).

3, 2, 5, 12, 25, 53, 116, 249, 535, 1155, 2487, 5358, 11545, 24871, 53584, 115444, 248715, 535841, 1154435, 2487154, 5358411, 11544347, 24871542, 53584111, 115443470, 248715414, 535841116, 1154434691, 2487154143, 5358411166

Offset: 1

Author

Amarnath Murthy, Jul 07 2001

Keywords

• base
• nonn

Comments

Sum of first 3n terms = 10^n.

Examples

			a(3) = 5 as there are 5 three-digit cubes: 125, 216, 343, 512 and 729.
		

Links

• Harry J. Smith, Table of n, a(n) for n = 1..300

Crossrefs

Cf. A062940.

Column k=3 of A216653.

Programs

Maple

r:= proc(n, k) local b; b:= iroot(n, k); b+`if`(b^k r(10^n, 3) -r(10^(n-1), 3) +`if`(n=1, 1, 0):
seq(a(n), n=1..40);  # Alois P. Heinz, Sep 12 2012

PARI

{ default(realprecision, 300); p=1; b=-1; for (n=1, 300, p*=10; c=b; b=floor((p - 1)^(1/3)); write("b062941.txt", n, " ", b - c) ) } \\ Harry J. Smith, Aug 14 2009

Extensions

Corrected and extended by Dean Hickerson, Jul 10 2001

Offset changed from 0 to 1 by Harry J. Smith, Aug 14 2009