OFFSET
1,1
COMMENTS
a(11) has 1258 decimal digits.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10
EXAMPLE
3, 323, 3233323,... are all palindromes.
MATHEMATICA
a[1]=3; a[n_]:=a[n]=(t=1; While[!IntegerQ[k=Min[FromDigits/@Select[Select[Tuples[{2, 3}, t], PrimeQ@FromDigits@#&], PalindromeQ@FromDigits@Flatten[{IntegerDigits/@Array[a, n-1], #}]&]]]||k<=a[n-1], t++]; k); Array[a, 5] (* Giorgos Kalogeropoulos, Sep 15 2021 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane and Chai Wah Wu, Sep 15 2021
STATUS
approved