A110015 - OEIS

%I #9 Sep 20 2016 10:45:08

%S 25,49,121,289,361,625,841,1369,1849,2209,2809,3025,3721,5041,5329,

%T 6241,7921,9409,10201,11449,11881,13225,16129,20449,24025,28561,29929,

%U 34969,36481,39601,46225,49729,55225,58081,63001,64009,69169,73441,78961

%N Squares of the form 6p + 7, where p is a prime.

%H Charles R Greathouse IV, <a href="/A110015/b110015.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = 6*A110014(n) + 7 = A110016(n)^2.

%t Select[6#+7&/@Prime[Range[8000]],IntegerQ[Sqrt[#]]&]  (* _Harvey P. Dale_, Mar 11 2011 *)

%o (PARI) forstep(n=5,1e3,[2,4], if(isprime((n^2-7)/6), print1(n^2", "))) \\ _Charles R Greathouse IV_, Sep 20 2016

%Y Cf. A110014, A110016.

%K nonn

%O 1,1

%A _Giovanni Teofilatto_, Sep 03 2005

%E Corrected and extended by _Ray Chandler_, Sep 04 2005