%I #17 Sep 08 2022 08:46:05
%S 3,1,3,1,3,1,9,1,3,3,1,1,3,1,3,27,3,1,1,9,1,1,3,9,1,3,1,27,1,3,1,3,3,
%T 1,3,1,1,1,3,3,9,1,3,1,9,1,1,1,3,1,9,3,1,9,3,3,27,1,1,3,1,3,1,3,1,3,1,
%U 1,3,1,3,9,1,1,1,3,3,1,3,1,3,1,27,1,1,3,9
%N Highest power of 3 dividing prime(n)+1.
%H Bruno Berselli, <a href="/A227991/b227991.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = 3^A227990(n).
%t Table[3^IntegerExponent[Prime[n] + 1, 3], {n, 100}]
%o (PARI) forprime(p=2, 700, print1(3^valuation(p+1, 3), ", "));
%o (Magma) [3^Valuation(NthPrime(n)+1, 3): n in [1..100]];
%Y Cf. A068503 (highest power of 3 dividing prime(n)-1), A068504 (highest power of 2 dividing prime(n)+1), A227990.
%K nonn
%O 1,1
%A _Bruno Berselli_, Aug 05 2013