A270097 Discriminator sequence for the powers of 2: smallest positive integer d such that 2^0, 2^1, ..., 2^{n-1} are all incongruent modulo d.

1, 2, 4, 5, 9, 9, 11, 11, 11, 11, 13, 13, 19, 19, 19, 19, 19, 19, 25, 25, 29, 29, 29, 29, 29, 29, 29, 29, 37, 37, 37, 37, 37, 37, 37, 37, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 53, 59, 59, 59, 59, 59, 59, 61, 61, 67, 67, 67, 67, 67, 67, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 101

Offset

0,2

Comments

The discriminator of a finite sequence s is the smallest positive integer d such that all the elements of s are incongruent modulo d. The sequence in question is the discriminator of the first n powers of 2.

Links

Table of n, a(n) for n=0..82.

Zhi-Wei Sun, On functions taking only prime values, J. Number Theory 133(2013), no.8, 2794-2812.

Crossrefs

Sequence in context: A116919 A270429 A359878 * A167511 A242398 A174112

Adjacent sequences: A270094 A270095 A270096 * A270098 A270099 A270100

Keyword

nonn

Author

Jeffrey Shallit, Mar 11 2016

Status

approved