a(n) is the smallest b > 1 such that when c is equal to any of the first n composites the congruence b^(c-1) == 1 (mod c) is satisfied, i.e., smallest b larger than 1 such that any member of the set of smallest n composites is a base-b Fermat pseudoprime.
A309383
a(n) is the smallest b > 1 such that when c is equal to any of the first n composites the congruence b^(c-1) == 1 (mod c) is satisfied, i.e., smallest b larger than 1 such that any member of the set of smallest n composites is a base-b Fermat pseudoprime.
Terms
- a(0) =5a(1) =13a(2) =25a(3) =73a(4) =361a(5) =361a(6) =2521a(7) =2521a(8) =5041a(9) =5041a(10) =5041a(11) =5041a(12) =55441a(13) =55441a(14) =277201a(15) =3603601a(16) =10810801a(17) =10810801a(18) =10810801a(19) =21621601a(20) =21621601a(21) =367567201a(22) =367567201a(23) =367567201
External references
- oeis: A309383