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A248512 Sequence based on repeating in turn the subtract, add and multiply operations on the previous 2 terms, starting with 0, 1.

%I A248512 #15 Sep 20 2021 19:02:02
%S A248512 0,1,1,2,2,0,2,0,-2,-2,4,6,10,60,50,110,5500,5390,10890,58697100,
%T A248512 58686210,117383310,6888781581155100,6888781463771790,
%U A248512 13777563044926890,94910620919839581404684194433100,94910620919839567627121149506210
%N A248512 Sequence based on repeating in turn the subtract, add and multiply operations on the previous 2 terms, starting with 0, 1.
%C A248512 After a(16) the sequence entries end 100, 90, 90, 100, 10, 10, 100, 90, 90, ... . - _Jon Perry_, Oct 29 2014
%F A248512 For n > 2,
%F A248512 If n mod 3 = 0, a(n) = a(n-1) - a(n-2),
%F A248512 If n mod 3 = 1, a(n) = a(n-1) + a(n-2),
%F A248512 If n mod 3 = 2, a(n) = a(n-1) x a(n-2),
%F A248512 a(1) = 0, a(2) = 1.
%t A248512 nxt[{n_,a_,b_}]:={n+1,b,Which[Mod[n+1,3]==0,b-a,Mod[n+1,3] == 1,a+b,True,a*b]}; NestList[nxt,{2,0,1},30][[All,2]] (* _Harvey P. Dale_, Sep 20 2021 *)
%K A248512 sign,easy
%O A248512 1,4
%A A248512 _Stuart E Anderson_, Oct 07 2014
%E A248512 More terms from _Colin Barker_, Oct 08 2014
%E A248512 Edited: Name changed and keyword easy added - _Wolfdieter Lang_, Oct 29 2014
%E A248512 Changed name. - _Jon Perry_, Oct 29 2014