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A193419
Numbers n such that 4n+3 is a palindromic prime.
0
0, 1, 2, 32, 37, 47, 95, 181, 196, 229, 2827, 2852, 3332, 3457, 3482, 3862, 3887, 4367, 4492, 4847, 4972, 4997, 7525, 7550, 7600, 7675, 7700, 8080, 8105, 8635, 8710, 9065, 9140, 9520, 9545, 9695, 17551, 17626, 17651, 18056, 18181, 18511, 18686, 19091, 19166
OFFSET
1,3
COMMENTS
The subsequence of primes p such that 4p+3 is a palindromic prime begins: 2, 37, 47, 181, 229, 3457.
FORMULA
{n such that A004767(n) is in A002385}.
EXAMPLE
a(1) = 2 because 4*2 + 3 = 11, and R(11) = 11 is prime.
a(2) = 37 because 4*37 + 3 = 151 is prime, and R(151) = 151.
MATHEMATICA
ppQ[n_]:=Module[{c=4n+3, d}, d=IntegerDigits[c]; PrimeQ[c]&&d == Reverse[ d]]; Select[Range[0, 20000], ppQ] (* Harvey P. Dale, Aug 02 2011 *)
CROSSREFS
KEYWORD
nonn,easy,base
AUTHOR
Jonathan Vos Post, Jul 26 2011
STATUS
approved