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A352605 Primes p such that the floor of the area of a triangle with sides p-1, p and p+1 is prime. 1

%I

%S 3,41,97,127,163,179,239,277,367,439,443,541,569,571,577,593,677,719,

%T 809,877,1013,1087,1201,1259,1439,1553,1601,1609,1721,1871,1879,1889,

%U 2063,2143,2179,2273,2281,2689,2803,2819,2887,3137,3313,3511,3527,3637,3797,3847,3911,4049,4091,4441,4933

%N Primes p such that the floor of the area of a triangle with sides p-1, p and p+1 is prime.

%C Primes p such that floor(p*sqrt(3*(p^2-4))/4) is prime.

%H Robert Israel, <a href="/A352605/b352605.txt">Table of n, a(n) for n = 1..10000</a>

%e a(3) = 97 is a term because 97 is prime, the area of a triangle with sides 96, 97 and 98 is 4073.35..., and 4073 is prime.

%p filter:= p -> isprime(floor(p/4*sqrt(3*(p^2-4)))):

%p select(filter, [seq(ithprime(i),i=1..10000)]);

%Y Cf. A096378.

%K nonn

%O 1,1

%A _J. M. Bergot_ and _Robert Israel_, Mar 22 2022

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Last modified October 1 22:45 EDT 2022. Contains 357173 sequences. (Running on oeis4.)