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%I #38 Mar 11 2024 08:30:18
%S 1,2,3,4,5,6,7,8,9,10,11,12,15,18,20,21,22,24,27,30,33,36,40,42,44,45,
%T 48,50,51,54,55,60,63,66,70,72,77,80,81,84,88,89,90,98,99,100,101,102,
%U 105,108,110,111,112,113,114,116,117,120,123,124,126,128
%N Numbers k such that the iterated subtraction of the decimal digits eventually reaches -k.
%C A180477 is a subsequence of this sequence. - _Hans Havermann_, Oct 27 2015
%H Reinhard Zumkeller, <a href="/A263808/b263808.txt">Table of n, a(n) for n = 1..10000</a>
%H Éric Angelini, <a href="http://list.seqfan.eu/oldermail/seqfan/2015-October/015519.html">Essicran Numbers</a>, SeqFan list, Oct 27 2015.
%e a(14)=18: 18-1-8-1-8-1-8-1-8 = -18. - _Bob Selcoe_, Oct 27 2015
%t eQ[n_] := Block[{d = IntegerDigits@ n}, MemberQ[Accumulate@ d ~Prepend~ 0, Mod[2*n, Total@ d]]]; Select[Range@ 128, eQ] (* _Giovanni Resta_, Oct 27 2015 *)
%o (Haskell)
%o a263808 n = a263808_list !! (n-1)
%o a263808_list = filter essicran [1..] where
%o essicran x = last (takeWhile (>= -x) es) == -x where
%o es = scanl (-) x (cycle $ map (read . return) $ show x)
%o (PARI) is(n)=my(d=digits(n),t,S=vector(#d-1,i,t+=d[i])); t=2*n%vecsum(d); t==0 || setsearch(S,d) \\ _Charles R Greathouse IV_, Oct 28 2015
%Y Cf. A005349, A180477.
%K nonn,base
%O 1,2
%A _Eric Angelini_ and _Reinhard Zumkeller_, Oct 27 2015