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 A096447 Odd primes p such that the number of primes less than p equal to 1 mod 4 is equal to the number of primes less than p equal to 3 mod 4. 18
 3, 7, 19, 43, 463, 26839, 26861, 26879, 26891, 26903, 26927, 616783, 616799, 616841, 616849, 616877, 617039, 617269, 617369, 617401, 617429, 617453, 617471, 617479, 617521, 617537, 617587, 617689, 617717, 617723, 618439, 618547, 618619, 618643 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS First term prime(2) = 3 is placed on 0th row. If prime(n-1) = +1 mod 4 is on k-th row then we put prime(n) on (k-1)-st row. If prime(n-1) = -1 mod 4 is on k-th row then we put prime(n) on (k+1)-st row. This process makes an array of prime numbers: 3, 7, 19, 43, ....0th row (this sequence) 5, 11, 17, 23, 31, 41, 47, 59, 67, 103, 127, .... first row (A096448) 13, 29, 37, 53, 61, 71, 79, 101, 107, 113 .... 2nd row (A096451) 73, 83, 97, 109, .... 3rd row 89, .... 4th row This is the next prime after A007351. - Joshua Zucker, May 03 2006 LINKS Giovanni Resta, Table of n, a(n) for n = 1..10000 MATHEMATICA lim = 10^5; k1 = 0; k3 = 0; p = 2; t = {}; Do[p = NextPrime[p]; If[k1 == k3, AppendTo[t, p]]; If[Mod[p, 4] == 1, k1++, k3++], {lim}]; t (* T. D. Noe, Sep 07 2011 *) CROSSREFS Cf. A096448-A096455. Cf. A007351, A096448-A096455. Sequence in context: A136041 A146685 A146653 * A274596 A185696 A141344 Adjacent sequences:  A096444 A096445 A096446 * A096448 A096449 A096450 KEYWORD nonn,easy AUTHOR Yasutoshi Kohmoto, Aug 12 2004 EXTENSIONS More terms from Joshua Zucker, May 03 2006 Added "odd" to definition. - N. J. A. Sloane, Sep 09 2015 STATUS approved

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Last modified March 28 17:51 EDT 2020. Contains 333103 sequences. (Running on oeis4.)