A234364 Primes which are the arithmetic mean of the squares of four consecutive primes.

157, 337, 673, 1213, 1777, 2137, 11677, 20773, 27259, 32803, 80407, 84787, 89227, 105397, 120097, 165313, 176461, 181513, 250543, 417337, 453667, 463807, 576883, 610867, 791317, 804757, 853873, 935167, 949687, 1087903

Offset: 1

Author

K. D. Bajpai, Dec 25 2013

Keywords

• nonn

Examples

			157 is in the sequence because (7^2 + 11^2 + 13^2 + 17^2)/4 = 157 which is prime.
1213 is in the sequence because (29^2 + 31^2 + 37^2 + 41^2)/4 = 1213 which is prime.
		

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..5666

Crossrefs

Cf. A084951: primes of the form (prime(k)^2 + prime(k+1)^2 + prime(k+2)^2)/3.

Cf. A093343: primes of the form (prime(k)^2 + prime(k+1)^2)/2.

Programs

Maple

KD := proc() local a,b,d,e,f,g; a:=ithprime(n); b:=ithprime(n+1); d:=ithprime(n+2); e:=ithprime(n+3); g:=(a^2+b^2+d^2+e^2)/4; if g=floor(g) and isprime(g) then RETURN (g);  fi;  end: seq(KD(), n=1..500);

Mathematica

Select[Table[Mean[Prime[Range[n, n + 3]]^2], {n, 250}], PrimeQ] (* Alonso del Arte, Dec 26 2013 *)
Select[Mean/@(Partition[Prime[Range[200]],4,1]^2),PrimeQ] (* Harvey P. Dale, Oct 08 2014 *)