Index of 6^n within the sequence of the numbers of the form 6^i*10^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) =90a(15) =102a(16) =115a(17) =129a(18) =144a(19) =159a(20) =175a(21) =192a(22) =210a(23) =228a(24) =247a(25) =267a(26) =288a(27) =310a(28) =332a(29) =355