A087844 - OEIS

%I #20 Jun 04 2018 18:27:55

%S 1,1,1,2,3,4,4,4,4,5,5,5,5,5,6,6,6,6,6,6,8,7,8,8,8,8,8,8,10,9,10,9,10,

%T 10,10,10,10,10,13,11,12,12,12,11,13,13,13,13,13,13,13,16,14,15,16,15,

%U 15,15,14,16,16,16,16,16,16,16,16,20,17,18,16,20,19,19,20,19,19,18,20

%N a(n) = a(a(a(min(n-1, abs(n - a(n-1)))))) + a(abs(n - a(n-3))).

%H Muniru A Asiru, <a href="/A087844/b087844.txt">Table of n, a(n) for n = 1..10000</a>

%p a:= proc(n) option remember: if n<4 then 1 else procname(procname(procname(min(n-1, abs(n-procname(n-1))))))+procname(abs(n-procname(n-3))) fi end:

%p seq(a(n),n=1..100); # _Muniru A Asiru_, Jun 02 2018

%t a[n_Integer?Positive] := a[n] = a[ a[a[Min[n-1, Abs[n - a[n-1]]]]]] + a[Abs[n - a[n-3]]]

%t a[0] = a[1] = a[2] = a[3] = 1

%t Table[a[n], {n, 1, 200}]

%o (GAP) a:=[1,1,1];; for n in [4..100] do a[n]:=a[a[a[Minimum(n-1,AbsInt(n-a[n-1]))]]]+a[AbsInt(n-a[n-3])]; od; a; # _Muniru A Asiru_, Jun 02 2018

%Y Cf. A005185, A081831.

%K nonn

%O 1,4

%A _Roger L. Bagula_, Oct 07 2003

%E Edited by _N. J. A. Sloane_, Jun 16 2007