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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A178316 Primes with the property that their digital rotation is still prime. 2
2, 5, 11, 19, 61, 101, 109, 151, 181, 199, 601, 619, 659, 661, 1019, 1021, 1061, 1091, 1109, 1129, 1151, 1181, 1201, 1229, 1259, 1291, 1511, 1559, 1601, 1609, 1621, 1669, 1699, 1811, 1901, 1999, 6011, 6091, 6101, 6199, 6211, 6221, 6229, 6521, 6551, 6569 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This means if written as in a digital clock and rotated 180 degrees around the center the result is also prime (possibly a different prime).

REFERENCES

Guy, R. K., Unsolved Problems in Number Theory, p 15 This sequence is related to the palindromic primes with symmetries as in Guy's book.

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000

EXAMPLE

For example 1259 becomes 6521 under such a rotation.

CROSSREFS

Cf. A007500, A055387, A018847.

Sequence in context: A276591 A051653 A106015 * A179632 A093871 A033263

Adjacent sequences:  A178313 A178314 A178315 * A178317 A178318 A178319

KEYWORD

nonn,base

AUTHOR

David Nacin, May 24 2010

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 April 25 00:29 EDT 2019. Contains 322446 sequences. (Running on oeis4.)