OFFSET
1,1
COMMENTS
Subset of A016026 for primes only.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Palindromic Primes
EXAMPLE
71 is the 20th prime and can be written as 131 in base 7, hence a(20)=7.
MATHEMATICA
PrimeMinBase[ n_ ] := NestWhile[ # + 1 &, 2, IntegerDigits[ Prime[ n ], # ] != Reverse[ IntegerDigits[ Prime[ n ], # ] ] & ]
sbr[n_]:=Module[{k=2}, While[IntegerDigits[n, k]!=Reverse[ IntegerDigits[ n, k]], k++]; k]; Table[sbr[n], {n, Prime[Range[80]]}] (* Harvey P. Dale, Jun 07 2016 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Peter Bertok (peter(AT)bertok.com), Nov 23 2001
STATUS
approved