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 A102138 #12 Apr 10 2020 15:48:42 %S A102138 4,6,7,12,25,72,100,126,167,253,396,856,1013,1172,1413,2138,23926, %T A102138 28255 %N A102138 Iccanobirt prime indices (8 of 15): Indices of prime numbers in A102118. %C A102138 No more terms through 5000. %C A102138 a(19) > 50000. - _Robert Price_, Nov 09 2018 %F A102138 A102118(a(n)) = A102158(n). %t A102138 a[n_] := a[n] = IntegerReverse[(a[n - 1] + a[n - 2] + a[n - 3])]; %t A102138 a[0] = 0; a[1] = 0; a[2] = 1; %t A102138 Select[Range[0, 5000], PrimeQ[a[#]] &] (* _Robert Price_, Apr 10 2020 *) %Y A102138 Cf. A000040, A102118, A102131-A102145. %K A102138 nonn,more,base %O A102138 1,1 %A A102138 _Jonathan Vos Post_ and _Ray Chandler_, Dec 31 2004 %E A102138 a(17)-a(18) from _Robert Price_, Nov 09 2018