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A162214
a(n) = the largest positive multiple of n with exactly n digits when written in binary.
3
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
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
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Jun 28 2009
EXTENSIONS
More terms from Alois P. Heinz, Jul 11 2009
STATUS
approved