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Numbers that cannot be written as a sum of distinct factorials.
4

%I #14 Jul 13 2013 12:03:23

%S 4,5,10,11,12,13,14,15,16,17,18,19,20,21,22,23,28,29,34,35,36,37,38,

%T 39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,

%U 62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85

%N Numbers that cannot be written as a sum of distinct factorials.

%C Complement of A059590; A115944(a(n)) = 0.

%H Reinhard Zumkeller, <a href="/A115945/b115945.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>

%t A059590 = Table[ Reverse[id = IntegerDigits[n, 2]].Range[ Length[id]]!, {n, 0, 20}]; Complement[ Range[ Last[A059590]], A059590] (* _Jean-François Alcover_, Jun 19 2012 *)

%o (Haskell)

%o import Data.List (elemIndices)

%o a115945 n = a115945_list !! (n-1)

%o a115945_list = elemIndices 0 $ map a115944 [0..]

%o -- _Reinhard Zumkeller_, Dec 04 2011

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Feb 02 2006