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 A076703 #6 Mar 30 2012 17:30:50
%S A076703 4,8,9,121,343,1331,10201,94249,1030301,900075181570009,
%T A076703 10022212521222001,12124434743442121,12323244744232321,
%U A076703 12341234943214321
%N A076703 Palindromic prime powers of prime numbers.
%C A076703 Up to 10^14, there are only 9 palindromic prime powers of prime numbers.
%t A076703 a = {}; Do[pp = Prime[n]^Prime[i]; d = IntegerDigits[pp]; If[d == Reverse[d], a = Append[a, pp]], {n, 1, PrimePi[ Sqrt[10^21]]}, {i, 1, PrimePi[ Floor[ Log[ Prime[n], 10^21]]]}]; Sort[a]
%Y A076703 Cf. A053810, A075308, subset of A072037.
%K A076703 nonn,base
%O A076703 1,1
%A A076703 _Zak Seidov_, Oct 26 2002
%E A076703 Edited and corrected by _Robert G. Wilson v_, Oct 31 2002