OFFSET
1,4
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..200
MATHEMATICA
f[n_] := Block[{k = 0, t = Flatten[ Join[{3}, Table[0, {n - 1}]]]}, While[s = Drop[t, Min[ -Floor[ Log[10, k]/2], 0]]; k != FromDigits[ Reverse[ IntegerDigits[k]]] || !PrimeQ[ FromDigits[ Join[s, IntegerDigits[k], Reverse[s]]]], k++ ]; k]; Table[ f[n], {n, 57}]
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Nov 23 2004
STATUS
approved