A061725 p^2 + 2 where p is a prime.

6, 11, 27, 51, 123, 171, 291, 363, 531, 843, 963, 1371, 1683, 1851, 2211, 2811, 3483, 3723, 4491, 5043, 5331, 6243, 6891, 7923, 9411, 10203, 10611, 11451, 11883, 12771, 16131, 17163, 18771, 19323, 22203, 22803, 24651, 26571, 27891, 29931

Offset

1,1

Comments

For any n >= 3, a(n) is of the form a(n) = 27 + 6m, m >= 0 integer. This follows from the simple fact that for any prime p >= 5, (p + 5)(p - 5) is divisible by 6. - Shai Covo (green355(AT)netvision.net.il), Oct 04 2010

References

David M. Burton, Elementary Number Theory, Allyn and Bacon, Inc. Boston, MA, 1976, pp. 51.

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Maple

A061725:=n->ithprime(n)^2+2: seq(A061725(n), n=1..50); # Wesley Ivan Hurt, Mar 17 2015

Mathematica

Prime[Range[40]]^2 + 2 (* Geoffrey Critzer, Feb 01 2015 *)

Prog

(PARI) v=[]; for(n=1, 100, v=concat(v, (prime(n)^2)+2)); v
(PARI) { n=0; forprime (p=2, prime(1000), write("b061725.txt", n++, " ", p^2 + 2) ) } \\ Harry J. Smith, Jul 27 2009
(Magma) [p^2+2: p in PrimesUpTo(200)]; // Vincenzo Librandi, Mar 22 2015

Crossrefs

Sequence in context: A140359 A136979 A007433 * A105708 A253908 A273504

Adjacent sequences: A061722 A061723 A061724 * A061726 A061727 A061728

Keyword

easy,nonn

Author

Jason Earls, Jun 23 2001

Status

approved