a(n) = the smallest positive integer that produces a product that contains the digit 2 when multiplied by 2 at most n times, and where a further multiplication by 2 produces a number that does not contain the digit 2. Set a(n) = -1 if no such number exists.
A381183
a(n) = the smallest positive integer that produces a product that contains the digit 2 when multiplied by 2 at most n times, and where a further multiplication by 2 produces a number that does not contain the digit 2. Set a(n) = -1 if no such number exists.
Terms
- a(0) =2a(1) =1a(2) =6a(3) =31a(4) =128a(5) =64a(6) =516a(7) =331a(8) =814a(9) =1607a(10) =4107a(11) =10158a(12) =10258a(13) =5129a(14) =10283a(15) =12819a(16) =25633a(17) =28141a(18) =16163a(19) =51404a(20) =80134a(21) =80864a(22) =40633a(23) =80216a(24) =40108a(25) =128129a(26) =250627a(27) =160626a(28) =80313a(29) =125641
External references
- oeis: A381183