A193419 Numbers n such that 4n+3 is a palindromic prime.
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
Examples
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.
Programs
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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 *)
Comments