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 A103836 #7 Mar 11 2021 21:06:46 %S A103836 3,11,181,373,12821,14741,32323,72227,74747,77977,78887,79997,90709, %T A103836 94049,94849,98689,1055501,1065601,1114111,1129211,1134311,1177711, %U A103836 1180811,1186811,1190911,1262621,1333331,1338331,1407041,1409041,1411141,1461641,1463641 %N A103836 Smallest palindromic prime p, larger than previous term, such that concatenation of n and p is a prime. %C A103836 Cf. A096915 %e A103836 a(4) = 373 because 4373 is prime, while 4191, 4313, 4353 are all composite. %o A103836 (Python) %o A103836 from sympy import isprime, nextprime %o A103836 def ispal(n): s = str(n); return s == s[::-1] %o A103836 def aupto(lim): %o A103836 n, p, alst = 1, 2, [] %o A103836 while p <= lim: %o A103836 if ispal(p) and isprime(int(str(n)+str(p))): n, alst = n + 1, alst + [p] %o A103836 p = nextprime(p) %o A103836 return alst %o A103836 print(aupto(1463641)) # _Michael S. Branicky_, Mar 11 2021 %Y A103836 Cf. A096915, A103835. %Y A103836 Subsequence of A002385. %K A103836 nonn,base %O A103836 1,1 %A A103836 _Zak Seidov_, Mar 30 2005