a(n) is the smallest prime p such that p^2 divides Bell(p+n) - Bell(n+1) - Bell(n).

Terms

a(0) =2a(1) =5a(2) =2a(3) =2a(4) =2a(5) =20663a(6) =2a(7) =229a(8) =2a(9) =2a(10) =2a(11) =11a(12) =2a(13) =5a(14) =2a(15) =2a(16) =2a(17) =23a(18) =2a(19) =3a(20) =2a(21) =2a(22) =2a(23) =101a(24) =2a(25) =3a(26) =2a(27) =2a(28) =2