This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A075241 Least base for which the n-th prime has no prime reversal in that base. 1
 2, 3, 5, 7, 4, 6, 3, 2, 6, 3, 7, 4, 4, 3, 4, 5, 2, 7, 10, 3, 3, 2, 6, 2, 3, 6, 2, 3, 2, 4, 4, 4, 2, 2, 2, 4, 2, 4, 4, 4, 2, 4, 2, 10, 3, 3, 2, 3, 4, 3, 9, 2, 2, 3, 3, 4, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 4, 3, 2, 4, 6, 4, 2, 3, 2, 3, 2, 2, 2, 5, 2, 4, 4, 3, 2, 3, 6, 2, 3, 4, 2, 3, 3, 6, 2, 4, 3, 4, 2, 2, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) is always less than or equal to n-th prime and once past a(6) it is always less than n. LINKS MATHEMATICA a = {}; Do[k = 2; p = Prime[n]; While[ PrimeQ[ FromDigits[ Reverse[ IntegerDigits[p, k]], k]], k++ ]; a = Append[a, k], {n, 1, 105}]; a CROSSREFS Sequence in context: A126607 A124322 A209037 * A239694 A097883 A290020 Adjacent sequences:  A075238 A075239 A075240 * A075242 A075243 A075244 KEYWORD base,easy,nonn AUTHOR Robert G. Wilson v, Sep 09 2002 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.

Last modified April 19 02:45 EDT 2019. Contains 322237 sequences. (Running on oeis4.)