Position of n-th 5 in A007376.

Terms

a(0) =5a(1) =21a(2) =41a(3) =61a(4) =81a(5) =90a(6) =92a(7) =94a(8) =96a(9) =98a(10) =100a(11) =101a(12) =102a(13) =104a(14) =106a(15) =108a(16) =121a(17) =141a(18) =161a(19) =181a(20) =207a(21) =237a(22) =267a(23) =297a(24) =327a(25) =341a(26) =344a(27) =347a(28) =350a(29) =353