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 A181841 #31 Jan 10 2022 22:09:22
%S A181841 7,11,23,59,179,383,503,719,1319,1439,1823,2579,2903,3119,3779,4283,
%T A181841 4679,4703,5099,5639,5939,6719,8783,8819,10079,12659,12983,13523,
%U A181841 15299,15683,16223,17483,18743,19079,21059,21383,21563,22643,23099,23603,24659,25343
%N A181841 Supersafe primes.
%C A181841 p is a supersafe prime iff p is a safe prime (A005385) and floor(p/3) is a prime.
%C A181841 Each prime p > 7 is preceded by two semiprimes; a third semiprime is not possible. See A036570. - _Zak Seidov_, Sep 30 2012
%C A181841 Terms > 7 are congruent to 11 (mod 12). - _Zak Seidov_, Feb 09 2015
%H A181841 Zak Seidov, <a href="/A181841/b181841.txt">Table of n, a(n) for n = 1..2000</a>
%H A181841 Peter Luschny, <a href="http://www.oeis.org/wiki/User:Peter_Luschny/StrongCoprimality">Strong coprimality</a>.
%e A181841 11 is a supersafe prime because floor(11/2) = 5 and floor(11/3) = 3 are primes.
%p A181841 A181841_list := n->select(i->isprime(iquo(i,3)),
%p A181841 select(i->isprime(iquo(i,2)), select(i->isprime(i),[$1..n]))):
%t A181841 Join[{7}, Select[Table[Prime[n], {n, 4000}], PrimeQ[(# - 1)/2] && PrimeQ[(# - 2)/3] &]] (* _Vladimir Joseph Stephan Orlovsky_, Jun 21 2011 *)
%Y A181841 Cf. A005385, A036570.
%K A181841 nonn
%O A181841 1,1
%A A181841 _Peter Luschny_, Nov 17 2010