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%I A102121 #10 Mar 23 2023 17:27:09
%S A102121 0,0,1,1,2,4,7,31,24,44,99,581,427,117,6201,6367,4018,8621,16342,
%T A102121 41752,18376,15486,185801,336123,551315,925189,7799571,5524929,
%U A102121 5346628,6800461,15116342,36822052,98232826,48616741,398264631,406948574
%N A102121 Iccanobirt numbers (11 of 15): a(n) = R(a(n-1) + R(a(n-2)) + R(a(n-3))), where R is the digit reversal function A004086.
%C A102121 Digit reversal variation of tribonacci numbers A000073.
%C A102121 Inspired by Iccanobif numbers: A001129, A014258-A014260.
%F A102121 a(n) = A004086(A102113(n)).
%t A102121 R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]+R[a[n-2]]+R[a[n-3]]];Table[a[n], {n, 0, 40}]
%t A102121 nxt[{a_,b_,c_}]:={b,c,IntegerReverse[c+IntegerReverse[b]+IntegerReverse[a]]}; NestList[ nxt,{0,0,1},40][[;;,1]] (* _Harvey P. Dale_, Mar 23 2023 *)
%Y A102121 Cf. A102111-A102125.
%K A102121 nonn,base,easy
%O A102121 0,5
%A A102121 _Jonathan Vos Post_ and _Ray Chandler_, Dec 30 2004

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