login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A155905 Numbers n such that it is possible to append a single digit to the end of 2^n to make it prime. 0
0, 1, 2, 3, 4, 6, 7, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 24, 25, 27, 30, 31, 33, 36, 38, 42, 43, 46, 49, 50, 51, 54, 55, 57, 58, 60, 64, 65, 73, 74, 84, 93, 106, 108, 123, 126, 129, 139, 150, 162, 183, 187, 196, 198, 220, 271, 273, 279, 301, 312, 379, 392 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Expected to be infinite because the harmonic series diverges.

LINKS

Table of n, a(n) for n=1..64.

EXAMPLE

For example 641 and 1283 are prime so 6 and 7 are in the sequence respectively.

CROSSREFS

Sequence in context: A250252 A246274 A057519 * A287531 A047518 A179834

Adjacent sequences:  A155902 A155903 A155904 * A155906 A155907 A155908

KEYWORD

nonn,base

AUTHOR

Dmitry Kamenetsky, Jan 30 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 10 04:15 EST 2019. Contains 329885 sequences. (Running on oeis4.)