A253971 Prime(n) is included iff prime(n) + n^2 is also prime.

2, 3, 7, 19, 37, 43, 79, 113, 151, 163, 193, 229, 251, 281, 317, 373, 397, 433, 463, 503, 577, 757, 827, 911, 953, 997, 1069, 1123, 1321, 1399, 1423, 1481, 1657, 1693, 1747, 2029, 2143, 2267, 2311, 2473, 2503, 2551, 2593, 2687, 2753, 2791, 2917, 3313, 3323

Offset

1,1

Links

Table of n, a(n) for n=1..49.

Formula

a(n) = prime(A064711(n)). - Michel Marcus, Feb 04 2015

Example

7 is in this sequence because 7+16=23.
19 is in this sequence because 19+64=83.

Mathematica

Prime[Select[Range[500], PrimeQ[Prime[#] + #^2] &]]

Prog

(Magma) [NthPrime(n): n in [1..500] | IsPrime(NthPrime(n)+n^2)];
(PARI) lista(nn) = forprime (n=2, nn, if (isprime(n+primepi(n)^2), print1(n, ", "))); \\ Michel Marcus, Feb 04 2015

Crossrefs

Cf. A064711, A061067.

Sequence in context: A298943 A340281 A172461 * A291339 A235616 A257551

Adjacent sequences: A253968 A253969 A253970 * A253972 A253973 A253974

Keyword

nonn

Author

Vincenzo Librandi, Feb 04 2015

Status

approved