Triangular numbers composed of digits {1,3,5}.

Terms

a(0) =1a(1) =3a(2) =15a(3) =55a(4) =153a(5) =351a(6) =5151a(7) =33153a(8) =35511a(9) =3531153a(10) =3555111a(11) =35133153a(12) =51151555a(13) =51313515a(14) =355311153a(15) =355551111a(16) =1553111511a(17) =5135151153a(18) =5351313331a(19) =15533353153a(20) =35553111153a(21) =35555511111a(22) =153335313531a(23) =155315331153a(24) =315331155153a(25) =355333351555