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A087831 a(n) = a(abs(n-a(n-1))) + a(a(abs(n-a(n-4)))) if n>4, a(n) = 1 otherwise. 2

%I

%S 1,1,1,1,1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,7,6,7,7,7,7,7,10,7,10,10,8,10,

%T 10,10,11,10,14,10,13,14,14,11,14,14,11,15,14,14,15,15,15,18,15,17,15,

%U 18,17,19,19,18,19,19,19,16,20,20,19,20,20,20,20,23,20,22,20,23,22,23,25

%N a(n) = a(abs(n-a(n-1))) + a(a(abs(n-a(n-4)))) if n>4, a(n) = 1 otherwise.

%C Second type of triple recursion for the skip two Hofstadter Q.

%t Hofstadter14[n_Integer?Positive] := Hofstadter14[n] = Hofstadter14[Abs[n - Hofstadter14[n-1]]] + Hofstadter14[ Hofstadter14[Abs[n - Hofstadter14[n-4]]]] Hofstadter14[0] = Hofstadter14[1] = Hofstadter14[2]= Hofstadter14[3]= Hofstadter14[4]= 1 digits=200 ta=Table[Hofstadter14[n], {n, 1, digits}]

%Y Cf. A005185.

%K nonn

%O 0,6

%A _Roger L. Bagula_, Oct 06 2003

%E Inserted a(0)=1 by _Paolo P. Lava_, Mar 12 2012

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Last modified November 29 13:17 EST 2021. Contains 349416 sequences. (Running on oeis4.)