OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..3793 (all terms < 10^14).
EXAMPLE
17 belongs to the sequence as for more than one one-digit base (2 and 4) its base representation is palindromic (in base 2 the representation is 10001, in base 4 the representation is 101).
13 does not belong to the sequence since only in one one-digit base (namely, base 3) is its base representation (111) palindromic.
PROG
(PARI) ispal(n, b)=my(v=digits(n, b)); for(i=1, #v\2, if(v[i]!=v[#v+1-i], return(0))); 1
is(n)=sum(b=2, 9, ispal(n, b))>1 && isprime(n) \\ Charles R Greathouse IV, Feb 21 2015
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Pierandrea Formusa, Feb 15 2015
STATUS
approved