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%I #4 Mar 30 2012 17:37:42
%S 1,2,3,380
%N Numbers n such that n=|d_1!!-d_2!!+...+(-1)^(k-1)*d_k!!| where d_1 d_2 ... d_k is the decimal expansion of n.
%e 380 is in the sequence because 380=|3!!-8!!+0!!|.
%t Do[h=IntegerDigits[n];l=Length[h];If[n==Abs[Sum[(-1)^(k-1) *h[[k]]!!, {k, l}]], Print[n]], {n, 4*9!!}]
%Y Cf. A097653, A097655, A097643.
%K base,fini,full,nonn
%O 1,2
%A _Farideh Firoozbakht_, Sep 10 2004
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