A111745 a(2k-1) = k-th prime congruent to 3 mod 4, a(2k) = k-th prime congruent to 1 mod 4.

3, 5, 7, 13, 11, 17, 19, 29, 23, 37, 31, 41, 43, 53, 47, 61, 59, 73, 67, 89, 71, 97, 79, 101, 83, 109, 103, 113, 107, 137, 127, 149, 131, 157, 139, 173, 151, 181, 163, 193, 167, 197, 179, 229, 191, 233, 199, 241, 211, 257, 223, 269, 227, 277, 239, 281, 251, 293, 263

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..1000

Formula

a(n)=A108546(n+1). [From R. J. Mathar, Aug 15 2008]

Mathematica

Module[{prs=Prime[Range[70]], m3, m1, min}, m3=Select[prs, Mod[#, 4]==3&]; m1=Select[prs, Mod[#, 4]==1&]; min=Min[Length[m1], Length[m3]]; Riffle[ Take[m3, min], Take[m1, min]]] (* Harvey P. Dale, Apr 15 2012 *)

Crossrefs

Cf. bisections A002144, A002145.

Sequence in context: A071810 A137576 A161329 * A098957 A143245 A018205

Adjacent sequences: A111742 A111743 A111744 * A111746 A111747 A111748

Keyword

nonn

Author

Jon Perry, Nov 19 2005

Extensions

Edited, corrected and extended by Franklin T. Adams-Watters, Jul 19 2006

Corrected by T. D. Noe, Nov 15 2006

Status

approved