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 A171836 #18 Nov 22 2024 11:02:21
%S A171836 61,109,181,331,397,463,727,787,877,991,1231,1303,1429,1669,1831,2029,
%T A171836 2137,2239,2539,2713,2797,3049,3253,3319,3517,3967,4093,4177,4603,
%U A171836 4723,5011,5113,5413,5659,5749,5851,6211,6379,6607,6793,6907,7297,7393,7789
%N A171836 a(n) = A002476(A002476(n)).
%C A171836 a(n) is the p-th prime == 1 (mod 6), where p is the n-th prime == 1 (mod 6). - _Robert Israel_, Nov 22 2024
%H A171836 Robert Israel, <a href="/A171836/b171836.txt">Table of n, a(n) for n = 1..10000</a>
%F A171836 a(n) = A002476(A002476(n)).
%e A171836 a(3) = 181 because A002476(3) = 19 is the third prime == 1 (mod 6), and A002476(19) = 181 is the 19th prime == 1 (mod 6). - _Robert Israel_, Nov 22 2024
%p A171836 A002476 := proc(n) if n= 1 then 7; else a := nextprime( procname(n-1)) ; while true do if a mod 6 = 1 then return a; end if; a := nextprime(a) ; end do ; end if; end proc: A171836 := proc(n) A002476(A002476(n)) ; end proc: seq(A171836(n),n=1..80) ; # _R. J. Mathar_, Jan 25 2010
%t A171836 With[{pr=Select[6*Range[2000]+1,PrimeQ]},Table[pr[[pr[[i]]]],{i,50}]] (* _Harvey P. Dale_, Dec 22 2013 *)
%Y A171836 Cf. A002476.
%K A171836 easy,nonn
%O A171836 1,1
%A A171836 _Jonathan Vos Post_, Dec 19 2009
%E A171836 More terms from _R. J. Mathar_, Jan 25 2010