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URL: https://oeis.org/A111744

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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.
2
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
OFFSET
1,1
COMMENTS
The graph shows the "race" between the two types of primes. - T. D. Noe, Nov 15 2006
LINKS
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
Cf. A108546.
Sequence in context: A131939 A393185 A205522 * A083781 A349156 A372313
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