login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A088148 Least number which when rotated through all its binary places produces n primes, not counting any repeats. 1
2, 5, 11, 43, 158, 2143, 2302, 2558, 36542, 548543, 711679, 786431, 9010423, 10452461 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

It is probably not the case that this always produces the same bit cycle as A088149. - Franklin T. Adams-Watters, Mar 29 2014

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

a(5) = 158 because 158 in base two is 10011110. This will produce eight possible new numbers; 00111101 = 61, 01111010 = 122, 11110100 = 244, 11101001 = 233, 11010011 = 211, 10100111 = 167, 01001111 = 79 and back to the beginning 10011110 = 158. Of those eight numbers (61, 122, 244, 233, 211, 167, 79 & 158) only five of them are primes. Notice that this is the same bit cycle as in A088149 but rotated differently.

MATHEMATICA

f[n_] := Count[ PrimeQ[ Union[ Table[ FromDigits[ RotateLeft[ IntegerDigits[n, 2], i], 2], {i, 1, Floor[ Log[2, n] + 1]}]]], True]; a = Table[0, {15}]; k = 1; Do[c = f[k]; If[c < 100 && a[[c+1]] == 0, a[[c+1]] = n]; k++, {n, 1, 10^7}]; a

CROSSREFS

Cf. A088149.

Sequence in context: A071313 A172297 A128231 * A088149 A153989 A160859

Adjacent sequences:  A088145 A088146 A088147 * A088149 A088150 A088151

KEYWORD

nonn,base

AUTHOR

Robert G. Wilson v, Sep 19 2003

EXTENSIONS

Edited by Franklin T. Adams-Watters, Mar 29 2014

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 January 25 01:49 EST 2020. Contains 331229 sequences. (Running on oeis4.)