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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A309979 Hash Parker numbers: Integers whose real 32nd root's first six nonzero digits (after the decimal point) rearranged in ascending order are equal to 234477. 0
4, 1191, 2340, 4915, 8101, 8703, 13937, 13952, 14029, 14041, 25111, 25127, 26062, 26203, 26324, 26479, 26490, 27934, 28077, 28195, 50506, 50536, 52216, 52359, 52892, 55703, 55957, 56030, 56059, 56075, 56178, 56244, 56566, 56577, 74747, 75877, 75952, 75996, 80752, 80764, 80765 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..41.

Matt Parker's YouTube Video, The A4 Paper Puzzle

EXAMPLE

4^(1/32) = 1.0442737824274138...

Rearranging 442737 in ascending order gives 234477.

1191^(1/32) = 1.2477346... -> 247734 -> 234477;

2340^(1/32) = 1.2743478... -> 274347 -> 234477.

PROG

(Haskell)

import Data.List

hash :: Double -> Inthash = read . sort . take 6 . filter (/='0') . drop 1 . dropWhile (/='.') . show . (** 0.03125)

main :: IO ()main = print $ map (floor . fst) . filter ((==234477) . snd) $ map (\x -> (x, hash x)) [2..1000000]

CROSSREFS

Sequence in context: A110499 A009013 A248656 * A221383 A198899 A253168

Adjacent sequences:  A309975 A309977 A309978 * A309981 A309982 A309983

KEYWORD

nonn,base

AUTHOR

Dan Dart, Aug 25 2019

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 22 10:24 EDT 2019. Contains 328317 sequences. (Running on oeis4.)