
COMMENTS

a(n) = A128049(n), where A128049(n) = {0,2,3,2,2,3,0,3,2,2,3,2,0,2,3,0,3,2,0,2,37,...} Least number k>0 such that (3^k  (3n)^k)/n is prime, or 0 if no such prime exists. a(3n) = 0. All positive terms are primes. a(50)a(67) = {7,0,79,2,0,2,109,0,5,5,0,2,5,0,131,2,0,2}. a(69)a(121) = {0,3,19,0,2,5,0,11,2,0,13,7,0,3,2,0,3,11,0,3,19,0,2,3,0,11,2,0,2,3,0,17,2,0,2,3,0,5,2,0,3,31,0,17,5,0,47,31,0,3,3,0,2}. a(123)a(127) = {0,3,2,0,3}. a(129)a(147) = {0,3,2,0,2,41,0,19,3,0,3,3,0,5,2,0,2,13,0}. a(149)a(162) = {7,0,2,3,0,439,3,0,2,359,0,3,2,0}. a(n)>541 = Prime[100] for n = {49,68,122,128,148,...}.
