login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A102831 Number of n-digit 4th powers. 0
2, 2, 2, 4, 8, 14, 25, 43, 78, 139, 246, 437, 779, 1384, 2461, 4376, 7783, 13840, 24612, 43765, 77828, 138400, 246114, 437658, 778280, 1383998, 2461136, 4376586, 7782795, 13839982, 24611356, 43765867, 77827942, 138399825, 246113559 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

The number 0 is considered a 1-digit 4th power. This is consistent with A062941 which considers 0 a 1-digit cube, but is inconsistent with A049415 which does not consider 0 a 1-digit square.

EXAMPLE

a(1)=2 because there are 2 1-digit 4th powers, 0 and 1.

MATHEMATICA

f[n_] := If[n == 1, 2, Ceiling[ Sqrt[ Sqrt[10^n]]] - Ceiling[ Sqrt[ Sqrt[10^(n - 1)]]]]; Table[ f[n], {n, 34}] (from Robert G. Wilson v Mar 03 2005)

CROSSREFS

Cf. A062941, A049415.

Sequence in context: A077943 A077993 A099768 * A183388 A160179 A021822

Adjacent sequences:  A102828 A102829 A102830 * A102832 A102833 A102834

KEYWORD

easy,nonn,base

AUTHOR

James Buddenhagen (jbuddenh(AT)gmail.com), Feb 27 2005

EXTENSIONS

More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 03 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 10:28 EST 2012. Contains 205763 sequences.