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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
OFFSET
1,1
LINKS
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: A371603 A248656 A357512 * A221383 A338104 A198899
KEYWORD
nonn,base
AUTHOR
Dan Dart, Aug 25 2019
STATUS
approved