Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
A028981
Primes p such that p+1 is palindromic.
1
2, 3, 5, 7, 43, 211, 241, 251, 271, 281, 433, 443, 463, 827, 857, 877, 887, 2111, 2221, 2441, 2551, 4003, 4663, 4993, 8117, 8447, 8887, 20101, 20201, 21011, 21211, 21611, 21911, 22621, 22721, 22921, 23131, 23431, 23531, 23831, 24841
OFFSET
1,1
LINKS
MATHEMATICA
palQ[n_] := Module[{idn = IntegerDigits[n + 1], len = Floor[IntegerLength[n + 1]/2]}, Take[idn, len] == Reverse[Take[idn, -len]]]; Select[Prime[Range[2800]], palQ] (* Harvey P. Dale, Nov 04 2011 *)
Select[Prime[Range[2800]], Reverse[x = IntegerDigits[# + 1]] == x &] (* Jayanta Basu, Jun 05 2013 *)
CROSSREFS
Cf. A027713.
Sequence in context: A120804 A092066 A224904 * A223035 A096843 A052016
KEYWORD
nonn,base
STATUS
approved