A143509 First of a pair of twin primes of the form n^2+x with x<2*n, or 0 if no such prime exist.

2, 5, 11, 17, 29, 41, 59, 71, 0, 107, 137, 149, 179, 197, 227, 269, 311, 347, 0, 419, 461, 521, 569, 599, 641, 0, 0, 809, 857, 0, 1019, 1031, 1091, 0, 1277, 1301, 1427, 1451, 0, 1607, 1697, 1787, 1871, 1949, 2027, 2129, 2237, 2309, 0, 2549, 2657, 2711, 0, 2969

Offset

1,1

Links

Pierre CAMI, Table of n, a(n) for n = 1..10000

Example

1^2+1=2 x=1, x<2*1 and 2 and 3 twin primes so a(1)=2
2^2+1=5 x=1, x<2*2 and 5 and 7 twin primes so a(2)=5
3^2+2=11 x=2, x<2*3 and 11 and 13 twin primes so a(3)=11

Crossrefs

Cf. A091592.

Sequence in context: A124850 A156850 A156611 * A111166 A064337 A076873

Adjacent sequences: A143506 A143507 A143508 * A143510 A143511 A143512

Keyword

nonn

Author

Pierre CAMI, Aug 21 2008

Status

approved