A110873 Squares of the form 8p - 7, where p is prime.

9, 49, 81, 225, 289, 529, 625, 1089, 1521, 1681, 2209, 3025, 5041, 6561, 7569, 7921, 9025, 10609, 12769, 14641, 16129, 16641, 18769, 20449, 22801, 23409, 28561, 31329, 36481, 37249, 39601, 40401, 46225, 49729, 50625, 69169, 70225, 73441, 78961

Offset: 1

Author

Giovanni Teofilatto, Sep 18 2005

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A055469, A067186, A110872.

Programs

Mathematica

Select[Table[n^2, {n, 300}], PrimeQ[(# + 7)/8] &] (* Ray Chandler, Oct 01 2005 *)
Select[8#-7&/@Prime[Range[1300]],IntegerQ[Sqrt[#]]&] (* Harvey P. Dale, Apr 11 2018 *)

PARI

for(i=1,1000,n=i^2+7;if(n%8==0&&isprime(n/8),print1(n-7,","))) (Klasen)

Formula

a(n) = A110872(n)^2 = 8*A055469(n) - 7.

a(n) = 8*A055469(n)-7.

Extensions

Extended by Lambert Klasen (lambert.klasen(AT)gmx.net) and Ray Chandler, Oct 01 2005