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 A185267 #13 Aug 28 2021 02:52:40 %S A185267 2,3,5,7,11,131,171,191,232,292,313,373,414,434,474,535,595,616,676, %T A185267 717,737,797,838,898,979,101,10301,10701,10901,11311,12721,131,13731, %U A185267 13931,14941,151,15751,16361,16761,17371,17971,181,191,19391,19791,1991,2112,22322 %N A185267 Smallest palindrome beginning with n-th prime. %C A185267 a(n) is itself prime for n = 1, 2, 3, 4, 5, 6, 8, 11, 12, 22, 26, 27, 30, 31, 32, 34, ... where a(n) = 2, 3, 5, 7, 11, 131, 191, 313, 373, 797, 101, 10301, 11311, 12721, 131, 13931, which are also in A002385. Although 979 begins with the prime p(25) = 97, and is a palindrome, it is not in the commented subsequence because 979 = 11 * 89 is semiprime rather than prime. %H A185267 T. D. Noe, <a href="/A185267/b185267.txt">Table of n, a(n) for n = 1..1000</a> %F A185267 a(n) = A082216(A000040(n)). %e A185267 a(6) = 131 because that is the smallest palindrome beginning (base 10) with p(6) = 13. %o A185267 (Python) %o A185267 from sympy import prime %o A185267 def A185267(n): %o A185267 p = prime(n) %o A185267 s = str(p) %o A185267 if s == s[::-1]: %o A185267 return p %o A185267 for i in range(1,len(s)): %o A185267 if s[i:] == s[-1:i-1:-1]: %o A185267 return int(s+s[i-1::-1]) # _Chai Wah Wu_, Aug 27 2021 %Y A185267 Cf. A000040, A002385, A082216. %K A185267 nonn,base,easy %O A185267 1,1 %A A185267 _Jonathan Vos Post_, Feb 19 2011