A162214 a(n) = the largest positive multiple of n with exactly n digits when written in binary.

1, 2, 6, 12, 30, 60, 126, 248, 504, 1020, 2046, 4092, 8190, 16380, 32760, 65520, 131070, 262134, 524286, 1048560, 2097144, 4194300, 8388606, 16777200, 33554425, 67108860, 134217702, 268435440, 536870910, 1073741820, 2147483646, 4294967264, 8589934584

Offset: 1

Author

Leroy Quet, Jun 28 2009

Keywords

• base
• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A162213.

Programs

Maple

a:= n-> n*floor((2^n-1)/n): seq(a(n), n=1..40); # Alois P. Heinz, Jul 11 2009

Mathematica

Array[# Floor[(2^# - 1)/#] &, 31] (* Michael De Vlieger, Nov 04 2017 *)

Formula

a(n) = n * floor((2^n-1)/n). - Alois P. Heinz, Jul 11 2009

Extensions

More terms from Alois P. Heinz, Jul 11 2009