Euler pseudoprimes to base 9: composite integers such that abs(9^((n - 1)/2)) == 1 mod n.

Terms

a(0) =4a(1) =28a(2) =91a(3) =121a(4) =286a(5) =532a(6) =671a(7) =703a(8) =949a(9) =1036a(10) =1105a(11) =1541a(12) =1729a(13) =1891a(14) =2465a(15) =2665a(16) =2701a(17) =2821a(18) =3281a(19) =3367a(20) =3751a(21) =4636a(22) =4961a(23) =5551a(24) =6364a(25) =6601a(26) =7381a(27) =8401a(28) =8911a(29) =10585