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A113243 Differences of nonzero tetranacci numbers.

%I A113243 #19 Jun 23 2024 11:44:38
%S A113243 0,1,2,3,4,6,7,11,13,14,21,25,27,28,41,48,52,54,55,79,93,100,104,106,
%T A113243 107,152,179,193,200,204,206,207,293,345,372,386,393,397,399,400,565,
%U A113243 665,717,744,758,765,769,771,772,1089,1282,1382,1434,1461,1475,1482
%N A113243 Differences of nonzero tetranacci numbers.
%H A113243 R. J. Mathar, <a href="/A113243/b113243.txt">Table of n, a(n) for n = 1..197</a>
%F A113243 {a(n)} = { A000078(i) - A000078(j) such that i>=j>=3 }.
%p A113243 isA113243 := proc(n)
%p A113243     local i,j ;
%p A113243     for j from 3 do
%p A113243         for i from 3 to j do
%p A113243             if A000078(j) - A000078(i) = n then
%p A113243                 return true;
%p A113243             elif A000078(j) - A000078(i) < n then
%p A113243                 break ;
%p A113243             end if;
%p A113243         end do:
%p A113243         if A000078(j) - A000078(j-1) > n then
%p A113243             return false;
%p A113243         end if;
%p A113243     end do:
%p A113243 end proc:
%p A113243 for n from 0 to 10000 do
%p A113243     if isA113243(n) then
%p A113243         printf("%d,",n) ;
%p A113243     end if;
%p A113243 end do: # _R. J. Mathar_, Oct 04 2014
%t A113243 Union[Flatten[Differences/@Subsets[Drop[LinearRecurrence[{1, 1, 1,1}, {0,0, 0, 1}, 16],3],{2}]]] (* _James C. McMahon_, Jun 23 2024 *)
%Y A113243 Cf. A000078, A113244.
%K A113243 easy,nonn
%O A113243 1,3
%A A113243 _Jonathan Vos Post_, Oct 19 2005; corrected Oct 20 2005