Index of first occurrence of n in A000319, or -1 if n never appears there.

Terms

a(0) =6a(1) =0a(2) =17a(3) =45a(4) =13a(5) =42a(6) =938a(7) =920a(8) =57403a(9) =7865a(10) =15862a(11) =313445a(12) =54988a(13) =53976a(14) =57573a(15) =61372a(16) =83445a(17) =14998a(18) =360213a(19) =57322a(20) =59858a(21) =2070497a(22) =2021631a(23) =14918a(24) =58001a(25) =1394543a(26) =79664a(27) =2056395a(28) =85989a(29) =11