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 A114786 #15 May 20 2019 02:49:48
%S A114786 0,43,0,47,44444444444444411,44444444413,44417,419,4423,4444444429,
%T A114786 431,444444437,4441,443,4447,44453,44444459,461,467,4444471,444473,
%U A114786 479,4483,44444489,44497,44101,444444103,444444444444107,444109,444113,4127
%N A114786 Smallest prime of the form: one or more 4's followed by prime(n) (or 0 if no such prime exists).
%C A114786 Prime(n) is all 0's followed by prime(n). a(n) is all 4's followed by prime(n). Conjecture: No term is zero for n > 3.
%C A114786 a(346) = 0 or a(346) > 5000, but note a(892) = 3612. - _D. S. McNeil_, Feb 04 2011
%e A114786 a(7) = 44417, as prime(7) = 17 and both 417 and 4417 are composite.
%t A114786 Table[If[n==1||n==3, 0, Select[FromDigits/@(Join[#,IntegerDigits[Prime[n]]]& /@ (Table[PadLeft[{4},k,4],{k,50}])),PrimeQ,1][[1]]],{n,35}] (* _Harvey P. Dale_, Feb 03 2011 *)
%Y A114786 Cf. A114783, A114784, A114785.
%K A114786 base,nonn
%O A114786 1,2
%A A114786 _Amarnath Murthy_, Nov 17 2005
%E A114786 More terms from _Joshua Zucker_, May 06 2006
%E A114786 Edited by _Jon E. Schoenfield_, May 19 2019