This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A102120 #10 Oct 30 2017 16:51:42
%S A102120 0,0,1,1,2,4,7,31,24,44,711,977,8311,1089,4023,53122,51475,33677,
%T A102120 412441,945145,6303211,1027527,8075903,51363612,74868455,376085401,
%U A102120 68539284,214889742,927862936,2360934421,2982905123,1968515515,8282454457
%N A102120 Iccanobirt numbers (10 of 15): a(n) = R(a(n-1) + R(a(n-2)) + a(n-3)), where R is the digit reversal function A004086.
%C A102120 Digit reversal variation of tribonacci numbers A000073.
%C A102120 Inspired by Iccanobif numbers: A001129, A014258-A014260.
%F A102120 a(n) = A004086(A102112(n)).
%t A102120 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]]+a[n-3]];Table[a[n], {n, 0, 40}]
%t A102120 nxt[{a_, b_, c_}] := {b, c, IntegerReverse[c + IntegerReverse[b] + a]}; NestList[nxt,{0,0,1},40][[All,1]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Oct 30 2017 *)
%Y A102120 Cf. A102111-A102125.
%K A102120 nonn,base,easy
%O A102120 0,5
%A A102120 _Jonathan Vos Post_ and _Ray Chandler_, Dec 30 2004