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 A102123 #8 Dec 19 2015 00:25:03
%S A102123 0,0,1,1,2,4,7,31,42,26,711,761,49,279,8811,1651,44311,38141,55006,
%T A102123 45901,34108,990681,161132,5891031,6129461,8041777,45820251,74839842,
%U A102123 60558487,202825861,635089352,309192535,7549098331,8252802091
%N A102123 Iccanobirt numbers (13 of 15): a(n) = R(R(a(n-1)) + a(n-2) + R(a(n-3))), where R is the digit reversal function A004086.
%C A102123 Digit reversal variation of tribonacci numbers A000073.
%C A102123 Inspired by Iccanobif numbers: A001129, A014258-A014260.
%F A102123 a(n) = A004086(A102115(n)).
%t A102123 R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[R[a[n-1]]+a[n-2]+R[a[n-3]]];Table[a[n], {n, 0, 40}]
%Y A102123 Cf. A102111-A102125.
%K A102123 nonn,base,easy
%O A102123 0,5
%A A102123 _Jonathan Vos Post_ and _Ray Chandler_, Dec 30 2004