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A110873
Squares of the form 8p - 7, where p is prime.
4
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
1,1
LINKS
FORMULA
a(n) = A110872(n)^2 = 8*A055469(n) - 7.
a(n) = 8*A055469(n)-7.
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 *)
PROG
(PARI) for(i=1, 1000, n=i^2+7; if(n%8==0&&isprime(n/8), print1(n-7, ", "))) (Klasen)
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Sep 18 2005
EXTENSIONS
Extended by Lambert Klasen (lambert.klasen(AT)gmx.net) and Ray Chandler, Oct 01 2005
STATUS
approved