A391314 Decimal expansion of log(2)/log(365/364).

2, 5, 2, 6, 5, 1, 9, 8, 8, 8, 4, 4, 1, 5, 7, 5, 9, 4, 3, 3, 0, 7, 2, 0, 1, 1, 6, 4, 9, 2, 2, 9, 0, 6, 6, 8, 3, 4, 2, 4, 6, 9, 6, 1, 8, 8, 5, 2, 1, 8, 3, 8, 5, 9, 5, 2, 4, 6, 5, 5, 8, 4, 3, 2, 2, 3, 3, 8, 6, 1, 7, 9, 3, 8, 7, 6, 5, 5, 5, 9, 0, 9, 0, 1, 5, 2, 0, 1, 2, 5

Offset

3,1

Comments

Ceiling of this constant (253) gives the minimum number of people (chosen randomly) such that the probability of at least one person in the group having the same birthday as a particular other person in the group (not considering leap years) is greater than 50%.

Links

Paolo Xausa, Table of n, a(n) for n = 3..10000

Brady Haran and Tom Crawford, Closer Look at the Birthday Paradox, YouTube Numberphile video, 2025.

Wikipedia, Birthday problem.

Example

252.65198884415759433072011649229066834246961885218...

Mathematica

First[RealDigits[Log[2]/Log[365/364], 10, 100]]

Crossrefs

Cf. A033810, A014088, A380129.

Sequence in context: A309431 A344077 A198539 * A121311 A242403 A179015

Adjacent sequences: A391311 A391312 A391313 * A391315 A391316 A391317

Keyword

nonn,cons,easy

Author

Paolo Xausa, Dec 06 2025

Status

approved