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

Author

Jeffrey Shallit, Mar 11 2016

Keywords

• nonn

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

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