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Primes which are an eighth of the sum of two consecutive primes.
2

%I #11 Dec 09 2024 01:57:06

%S 3,19,59,89,109,149,151,317,331,359,389,401,439,571,599,829,941,953,

%T 1019,1153,1249,1279,1319,1373,1381,1451,1657,1669,1733,1741,1867,

%U 1871,1973,2131,2161,2179,2251,2459,2819,3119,3539,3659,3967,4001,4099,4231,4261

%N Primes which are an eighth of the sum of two consecutive primes.

%C Primes of the form A001043(k)/8.

%H Robert Israel, <a href="/A164132/b164132.txt">Table of n, a(n) for n = 1..10000</a>

%e 19 is there because it is prime and 19=(73+79)/8.

%p p:= 2: R:= NULL: count:= 0:

%p while count < 100 do

%p q:= p; p:= nextprime(p);

%p v:= (q+p)/8;

%p if v::integer and isprime(v) then

%p R:= R,v; count:= count+1;

%p fi;

%p od:

%p R; # _Robert Israel_, Dec 08 2024

%t Select[Total[#]/8&/@Partition[Prime[Range[2500]],2,1],PrimeQ] (* _Harvey P. Dale_, Apr 22 2011 *)

%Y Cf. A000040, A118134, A163487.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Aug 11 2009

%E Extended by _R. J. Mathar_, Aug 27 2009