Least number k>1 such that (tau(k-1)+tau(k+1))/tau(k) = n where tau = A000005.

Terms

a(0) =6a(1) =34a(2) =39a(3) =7a(4) =11a(5) =19a(6) =29a(7) =41a(8) =79a(9) =71a(10) =179a(11) =199a(12) =181a(13) =239a(14) =883a(15) =419a(16) =701a(17) =839a(18) =881a(19) =1429a(20) =2351a(21) =1259a(22) =1871a(23) =2161a(24) =4049a(25) =3079a(26) =3361a(27) =2521a(28) =6481a(29) =4159