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A111744 a(2k-1) = k-th prime of form 1 mod 4, a(2k) = k-th prime of form 3 mod 4. 1
5, 3, 13, 7, 17, 11, 29, 19, 37, 23, 41, 31, 53, 43, 61, 47, 73, 59, 89, 67, 97, 71, 101, 79, 109, 83, 113, 103, 137, 107, 149, 127, 157, 131, 173, 139, 181, 151, 193, 163, 197, 167, 229, 179, 233, 191, 241, 199, 257, 211, 269, 223, 277, 227, 281, 239, 293, 251, 313 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The graph shows the "race" between the two types of primes. - T. D. Noe, Nov 15 2006

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..10000

MATHEMATICA

Module[{nn=100, pr, m1, m3, len}, pr=Prime[Range[nn]]; m1=Select[pr, Mod[#, 4] == 1&]; m3=Select[pr, Mod[#, 4]==3&]; len=Min[Length[m1], Length[m3]]; Flatten[ Thread[ {Take[m1, len], Take[m3, len]}]]] (* Harvey P. Dale, Jun 29 2019 *)

CROSSREFS

Sequence in context: A300940 A131939 A205522 * A083781 A349156 A206435

Adjacent sequences:  A111741 A111742 A111743 * A111745 A111746 A111747

KEYWORD

nonn

AUTHOR

Jon Perry, Nov 19 2005

EXTENSIONS

Corrected and extended by Wendy Kalasky (wkk107(AT)psu.edu), Apr 25 2006

Corrected by T. D. Noe, Nov 15 2006

STATUS

approved

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Last modified December 6 16:37 EST 2021. Contains 349567 sequences. (Running on oeis4.)