A226950 Higher powers having partitions into distinct higher powers in more than one way.
7449150177, 8936757492481, 11587386200625, 22449633661000, 30511719124992, 36443545848801, 283680450809856, 583096733580816, 613579106939841, 3958783819215057, 4098048384032001, 4556608567054336, 13469350037585841, 23887131799781376, 36604958689202176, 58634065908167841, 69952404620958561, 91953699475456000, 124976001535967232, 149272763796688896, 183001280170947121, 225430653627891712
Offset: 1
Keywords
Examples
a(1) = 7449150177 = 1953^3 = 1116^3 + 279^4 = 217^4 + 1736^3; a(2) = 8936757492481 = 1729^4 = 1729^3 + 20748^3 = 15561^3 + 17290^3; see link for more examples and more info.
Links
- Reinhard Zumkeller, First 22 terms of A226950
Programs
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Haskell
import qualified Data.Set as Set (split, filter) import Data.Set (Set, empty, size, insert, member) a226950 n = a226950_list !! (n-1) a226950_list = f a076467_list empty where f (x:xs) s | size s'' <= 1 = f xs (x `insert` s) | otherwise = x : f xs (x `insert` s) where s'' = Set.filter ((`member` s) . (x -)) s' (s', _) = Set.split (x `div` 2) s
Comments