A075241 Least base for which the n-th prime has no prime reversal in that base.

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

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

Amiram Eldar, Table of n, a(n) for n = 1..10000

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

Cf. A075240, A075242.

Sequence in context: A124322 A209037 A334455 * 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