login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A061434 a(n) is the smallest n-digit cube. 4
1, 27, 125, 1000, 10648, 103823, 1000000, 10077696, 100544625, 1000000000, 10007873875, 100026577288, 1000000000000, 10000909453625, 100000721719296, 1000000000000000, 10000073940248384, 100000075387171679, 1000000000000000000, 10000004316234262875 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = ceiling(10^((n-1)/3))^3. - Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
EXAMPLE
a(4) = 1000 = 10^3 has 4 digits while 9^3 = 729 has 3 digits.
MAPLE
A061434 := n->ceil(10^((n-1)/3))^3;
MATHEMATICA
Table[Ceiling[Surd[10^n, 3]]^3, {n, 0, 20}] (* Harvey P. Dale, Oct 09 2023 *)
PROG
(Python)
from sympy import integer_nthroot
def a(n):
r, exact = integer_nthroot(10**(n-1), 3)
return 10**(n-1) if exact else (r+1)**3
print([a(n) for n in range(1, 21)]) # Michael S. Branicky, Jan 27 2021
(PARI) a(n) = ceil(10^((n-1)/3))^3; \\ Michel Marcus, Jan 27 2021
CROSSREFS
Sequence in context: A016755 A074100 A082610 * A092770 A253103 A321486
KEYWORD
nonn,base,easy
AUTHOR
Amarnath Murthy, May 03 2001
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)