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 A078394 #13 Aug 21 2025 10:01:27
%S A078394 0,1,2,3,4,39,256
%N A078394 Numbers k such that reverse(A004154(k)) + 1 is prime.
%C A078394 Some of the larger entries may only correspond to probable primes.
%C A078394 a(8) > 25000. - _Michael S. Branicky_, Aug 20 2025
%t A078394 f[n_] := n!/10^Sum[Floor[n/5^k], {k, 1, Log[10, n] + 1}]; Do[ If[ PrimeQ[ FromDigits[ Reverse[ IntegerDigits[ f[n]]]] + 1], Print[n]], {n, 0, 800}]
%Y A078394 Cf. A078203, A004154.
%K A078394 base,more,nonn
%O A078394 1,3
%A A078394 _Jason Earls_, Dec 24 2002
%E A078394 a(1) = 0 inserted by _Michael S. Branicky_, Aug 20 2025