Position of n-th 5 in A031324.

Terms

a(0) =4a(1) =12a(2) =13a(3) =32a(4) =36a(5) =46a(6) =60a(7) =68a(8) =71a(9) =90a(10) =117a(11) =120a(12) =123a(13) =136a(14) =143a(15) =148a(16) =165a(17) =176a(18) =177a(19) =180a(20) =181a(21) =240a(22) =248a(23) =266a(24) =274a(25) =279a(26) =289a(27) =297a(28) =313a(29) =322