a(n) is the smallest positive integer k such that the last n digits of 2^k are 1 or 2.
A147884
a(n) is the smallest positive integer k such that the last n digits of 2^k are 1 or 2.
Terms
- a(0) =1a(1) =9a(2) =89a(3) =89a(4) =589a(5) =3089a(6) =3089a(7) =3089a(8) =315589a(9) =315589a(10) =8128089a(11) =164378089a(12) =945628089a(13) =1922190589a(14) =11687815589a(15) =109344065589a(16) =231414378089
External references
- oeis: A147884