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 A078190 #13 Aug 07 2015 02:40:21
%S A078190 5,23,11,71,503,62270207,871782911,121645100408831,243290200817663,
%T A078190 304888344611713860501503,137637530912263450463159795815809023
%N A078190 Primes of the form A004154(n) - 1.
%C A078190 More precisely, scan A004154, subtract 1 and record the answer if it is a prime. The sequence is not monotonic.
%H A078190 Charles R Greathouse IV, <a href="/A078190/b078190.txt">Table of n, a(n) for n = 1..17</a>
%p A078190 A004154 := proc(n) option remember ; local m ; if n <= 1 then RETURN(1) ; else m := A004154(n-1)*n ; while m mod 10 = 0 do m := m /10 ; end ; RETURN(m) ; fi ; end: n := 1 ; while true do f := A004154(n) : if isprime(f-1) then printf("%d, ",f-1) ; fi ; n := n+1 : od : # _R. J. Mathar_, Feb 27 2007
%o A078190 (PARI) v=[];for(n=1,500,if(ispseudoprime(t=n!/10^valuation(n!,5)-1),v=concat(v,t))); v \\ _Charles R Greathouse IV_, Feb 14 2011
%Y A078190 Cf. A004154, A078154, A078203, A078305.
%K A078190 nonn
%O A078190 1,1
%A A078190 _Cino Hilliard_, Dec 23 2002
%E A078190 More terms from _R. J. Mathar_, Feb 27 2007