Numbers which can be expressed as the product of numbers made of only threes.

Terms

a(0) =1a(1) =3a(2) =9a(3) =27a(4) =33a(5) =81a(6) =99a(7) =243a(8) =297a(9) =333a(10) =729a(11) =891a(12) =999a(13) =1089a(14) =2187a(15) =2673a(16) =2997a(17) =3267a(18) =3333a(19) =6561a(20) =8019a(21) =8991a(22) =9801a(23) =9999a(24) =10989a(25) =19683a(26) =24057a(27) =26973a(28) =29403a(29) =29997