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A102117 Iccanobirt numbers (7 of 15): a(n) = R(a(n-1)) + R(a(n-2)) + R(a(n-3)), where R is the digit reversal function A004086.

%I A102117 #13 Aug 04 2016 02:59:17
%S A102117 0,0,1,1,2,4,7,13,42,62,81,68,130,135,648,1408,9418,17036,79261,87517,
%T A102117 150946,736926,1350266,7899219,16380155,70858879,162124155,704415429,
%U A102117 1573821475,7217219419,15814925285,73143352729,160127403115
%N A102117 Iccanobirt numbers (7 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 A102117 Digit reversal variation of tribonacci numbers A000073.
%C A102117 Inspired by Iccanobif numbers: A001129, A014258-A014260.
%H A102117 Robert Israel, <a href="/A102117/b102117.txt">Table of n, a(n) for n = 0..2664</a>
%F A102117 A004086(a(n)) = A102125(n).
%p A102117 rev:= proc(n) local i, L;
%p A102117 L:= convert(n,base, 10);
%p A102117 add(L[-i]*10^(i-1),i=1..nops(L))
%p A102117 end proc:
%p A102117 A[0]:= 0: A[1]:= 0: A[2]:= 1:
%p A102117 RA[0]:=0: RA[1]:= 0: RA[2]:= 1:
%p A102117 for n from 3 to 100 do
%p A102117   A[n]:= RA[n-1]+RA[n-2]+RA[n-3];
%p A102117   RA[n]:= rev(A[n]);
%p A102117 od:
%p A102117 seq(A[n],n=0..100); # _Robert Israel_, Aug 04 2016
%t A102117 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 A102117 nxt[{a_,b_,c_}]:={b,c,Total[IntegerReverse/@{a,b,c}]}; Transpose[ NestList[ nxt,{0,0,1},40]][[1]] (* The program uses the IntegerReverse function from Mathematica version 10 *) (* _Harvey P. Dale_, Nov 28 2015 *)
%Y A102117 Cf. A102111-A102125.
%K A102117 nonn,base,easy
%O A102117 0,5
%A A102117 _Jonathan Vos Post_ and _Ray Chandler_, Dec 30 2004