A186233 The number of lucky numbers between n and 2n, exclusive.

0, 1, 0, 1, 2, 2, 2, 3, 2, 2, 3, 3, 3, 3, 2, 3, 4, 4, 5, 5, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 5, 6, 5, 6, 7, 7, 7, 8, 8, 9, 9, 9, 8, 9, 9, 9, 10, 10, 9, 10, 9, 9, 10, 10, 10, 11, 11, 12, 12, 12, 12, 12, 11, 12, 13, 13, 13, 14, 13, 13, 14, 14, 13, 13, 12, 13, 13, 13, 12, 13, 13, 14, 14, 14, 15, 16, 15, 15, 15, 15, 15, 15, 14, 14, 15, 15, 16, 17, 16, 16

Offset

1,5

Comments

There is a lucky number between n and 2n for all n >= 4. There are at least n lucky numbers between x/2 and x for all x >= A186234(n).

Links

Table of n, a(n) for n=1..100.

Crossrefs

Cf. A000959 (lucky numbers)

Sequence in context: A138789 A129654 A116504 * A226056 A104011 A242879

Adjacent sequences: A186230 A186231 A186232 * A186234 A186235 A186236

Keyword

nonn

Author

T. D. Noe, Feb 15 2011

Status

approved