Index of 3^n within the sequence of the numbers of the form 3^i*4^j.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =11a(5) =15a(6) =20a(7) =26a(8) =33a(9) =41a(10) =49a(11) =58a(12) =68a(13) =79a(14) =91a(15) =103a(16) =116a(17) =130a(18) =145a(19) =161a(20) =177a(21) =194a(22) =212a(23) =231a(24) =251a(25) =271a(26) =292a(27) =314a(28) =337a(29) =360