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A096451 Primes p such that the number of primes less than p equal to 1 mod 4 is two less than the number of primes less than p equal to 3 mod 4. 3

%I #16 Nov 08 2018 08:53:52

%S 13,29,37,53,61,71,79,101,107,113,131,139,151,163,199,359,409,421,433,

%T 443,457,479,1223,1231,1249,1277,1283,1291,1301,1307,1399,1423,1439,

%U 8699,8779,26821,26951,26959,26987,27011,27031,615731,615869,615887

%N Primes p such that the number of primes less than p equal to 1 mod 4 is two less than the number of primes less than p equal to 3 mod 4.

%C First term prime(2) = 3 is placed on 0th row.

%C If prime(n-1) = +1 mod 4 is on k-th row then we put prime(n) on (k-1)-st row.

%C If prime(n-1) = -1 mod 4 is on k-th row then we put prime(n) on (k+1)-st row.

%C This process makes an array of prime numbers:

%C 3, 7, 19, 43, ....0th row

%C 5, 11, 17, 23, 31, 41, 47, 59, 67, 103, 127, ....first row

%C 13, 29, 37, 53, 61, 71, 79, 101, 107, 113 ....2nd row

%C 73, 83, 97, 109, ....3rd row

%C 89, ....4th row

%H Robert Israel, <a href="/A096451/b096451.txt">Table of n, a(n) for n = 1..811</a>

%H Andrew Granville and Greg Martin, <a href="http://www.jstor.org/stable/27641834">Prime number races</a>, Amer. Math. Monthly, 113 (No. 1, 2006), 1-33.

%p c1:= 0; c3:= 0: p:= 2: count:= 0: Res:= NULL:

%p while count < 100 do

%p p:= nextprime(p);

%p if c1 = c3 - 2 then

%p count:= count+1;

%p Res:= Res, p;

%p fi;

%p if p mod 4 = 1 then c1:=c1+1

%p else c3:= c3+1

%p fi

%p od:

%p Res; # _Robert Israel_, Nov 07 2018

%Y Cf. A096447-A096455.

%Y Cf. A002144, A002145, A007350, A007351

%K nonn

%O 1,1

%A _Yasutoshi Kohmoto_, Aug 12 2004

%E More terms from _Joshua Zucker_, May 03 2006

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Last modified September 19 06:28 EDT 2024. Contains 376004 sequences. (Running on oeis4.)