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A096448 Primes p such that the number of primes less than p equal to 1 mod 4 is one less than the number of primes less than p equal to 3 mod 4. 13

%I

%S 5,11,17,23,31,41,47,59,67,103,127,419,431,439,461,467,1259,1279,1303,

%T 26833,26849,26881,26893,26921,26947,615883,616769,616787,616793,

%U 616829,617051,617059,617087,617257,617473,617509,617647,617681,617731,617819

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

%t Prime[#]&/@(Flatten[Position[Accumulate[If[Mod[#,4]==1,1,-1]&/@ Prime[ Range[ 2,51000]]],-1]]+2) (* _Harvey P. Dale_, Mar 08 2015 *)

%Y Cf. A096447-A096455.

%Y Cf. A096448-A096455.

%K nonn,easy

%O 1,1

%A _Yasutoshi Kohmoto_, Aug 12 2004

%E More terms from _Joshua Zucker_, May 03 2006

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Last modified June 6 01:51 EDT 2020. Contains 334858 sequences. (Running on oeis4.)