A100748 Years of recorded appearances of Halley's Comet (negative years are B.C.).

-240, -164, -86, -11, 66, 141, 218, 295, 374, 451, 530, 607, 684, 760, 837, 912, 989, 1066, 1145, 1222, 1301, 1378, 1456, 1531, 1607, 1682, 1759, 1835, 1910, 1985

Offset

1,1

Comments

This sequence is not well-defined for many reasons (negative years are ill-defined; calendars change often, so when does a year begin?; what does "observed" mean?; what if the comet was observed both at the end of one year and at the beginning of another, as in 1985/1986?; etc.). - N. J. A. Sloane, Jun 24 2007

Links

Table of n, a(n) for n=1..30.

Joseph M. Laufer, Halley's Comet, Its 30th Recorded Return, 1985-1986.

Example

a(30) = 1985 because the 30th recorded appearance of Halley's comet was in 1985.

Crossrefs

See A072235 for another version.

Sequence in context: A299587 A078151 A278179 * A072235 A298453 A121378

Adjacent sequences: A100745 A100746 A100747 * A100749 A100750 A100751

Keyword

sign

Author

David Terr, Jan 03 2005

Status

approved