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 A077623 a(1)=1, a(2)=2, a(3)=4, a(n) = abs(a(n-1)-a(n-2)-a(n-3)). 9

%I

%S 1,2,4,1,5,0,6,1,5,2,4,3,3,4,2,5,1,6,0,7,1,6,2,5,3,4,4,3,5,2,6,1,7,0,

%T 8,1,7,2,6,3,5,4,4,5,3,6,2,7,1,8,0,9,1,8,2,7,3,6,4,5,5,4,6,3,7,2,8,1,

%U 9,0,10,1,9,2,8,3,7,4,6,5,5,6,4,7,3,8,2,9,1,10,0,11,1,10,2,9,3,8,4,7,5,6,6

%N a(1)=1, a(2)=2, a(3)=4, a(n) = abs(a(n-1)-a(n-2)-a(n-3)).

%H Reinhard Zumkeller, <a href="/A077623/b077623.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n)/sqrt(n) is bounded. More precisely, let M(n) = Max ( a(k) : 1<=k<=n ); then M(n)= floor(sqrt(n+29)) for n>=4

%o a077623 n = a077623_list !! (n-1)

%o a077623_list = 1 : 2 : 4 : zipWith3 (\u v w -> abs (w - v - u))

%o a077623_list (tail a077623_list) (drop 2 a077623_list)

%o -- _Reinhard Zumkeller_, Oct 11 2014

%Y Cf. A077653, A079623, A079624, A080096, A088226.

%K nonn

%O 1,2

%A _Benoit Cloitre_, Dec 02 2002

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Last modified June 7 02:48 EDT 2020. Contains 334836 sequences. (Running on oeis4.)