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

1,2

Links

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

Formula

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

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 *)

Crossrefs

Cf. A162213.

Sequence in context: A058215 A330542 A166456 * A309728 A100071 A331552

Adjacent sequences: A162211 A162212 A162213 * A162215 A162216 A162217

Keyword

base,nonn

Author

Leroy Quet, Jun 28 2009

Extensions

More terms from Alois P. Heinz, Jul 11 2009

Status

approved