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A164580
Primes of the form p^2 + (p + 1)/2 where p is also prime.
2
11, 53, 127, 541, 977, 1871, 3511, 4523, 5077, 11503, 16193, 19391, 22877, 57241, 63127, 80231, 129061, 134873, 143831, 229681, 241327, 344863, 359101, 398477, 418933, 434611, 619763, 658127, 745201, 845021, 966781, 982577, 1063477, 1130501, 1371827
OFFSET
1,1
LINKS
FORMULA
a(n) = (A154427(n))^2 + ( A154427(n)+1)/2.
EXAMPLE
For p=3, p^2+(p+1)/2=11, prime, which adds 11 to the sequence. For p=7, p^2+(p+1)/2=53, which adds 53 to the sequence.
MATHEMATICA
Select[Table[p^2 + (p + 1)/2, {p, Prime[Range[200]]}], PrimeQ] (* Vincenzo Librandi, Oct 12 2012 *)
PROG
(Magma) [a: p in PrimesInInterval(3, 1200) | IsPrime(a) where a is p^2 + (p+1) div 2 ]; // Vincenzo Librandi, Oct 12 2012
CROSSREFS
Cf. A154427.
Sequence in context: A086715 A178453 A225582 * A141893 A093198 A207361
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Aug 17 2009
EXTENSIONS
Edited and extended by R. J. Mathar, Aug 26 2009
STATUS
approved