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 A070028 #7 Mar 30 2012 17:36:38 %S A070028 2,3,5,7,11,113,131,311,11111111111111111111111 %N A070028 Absolute primes: primes whose initial, all intermediate and final sums of digits are primes. %C A070028 The next terms are R(317) and R(1031) where R(n)=(10^n-1)/9 is a repunit prime. This sequence is a subsequence of A003459 and A070027. %e A070028 113 is a term because 113 and permutations 131 and 311 are prime as is 1+1+3=5. 11111111111111111111111 is a term because it is prime, all permutations of its digits are prime, the sum of its digits, 23, is prime and 2+3=5 is also prime. %Y A070028 Cf. A003459 (absolute primes), A004022 (repunit primes), A070027. %K A070028 base,nonn %O A070028 1,1 %A A070028 _Rick L. Shepherd_, Apr 15 2002