A039702 - OEIS

A039702

a(n) = n-th prime modulo 4.

2, 3, 1, 3, 3, 1, 1, 3, 3, 1, 3, 1, 1, 3, 3, 1, 3, 1, 3, 3, 1, 3, 3, 1, 1, 1, 3, 3, 1, 1, 3, 3, 1, 3, 1, 3, 1, 3, 3, 1, 3, 1, 3, 1, 1, 3, 3, 3, 3, 1, 1, 3, 1, 3, 1, 3, 1, 3, 1, 1, 3, 1, 3, 3, 1, 1, 3, 1, 3, 1, 1, 3, 3, 1, 3, 3, 1, 1, 1, 1, 3, 1, 3, 1, 3, 3, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 1, 1, 3, 1, 3, 1, 3, 1, 3

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Except for the first term, A100672(n) = (A039702(n)-1)/2 = parity of A005097. - Jeremy Gardiner, May 17 2008

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

MAPLE

seq(ithprime(n) mod 4, n=1..105); # Nathaniel Johnston, Jun 29 2011

MATHEMATICA

Table[Mod[Prime[n], 4], {n, 105}] (* Nathaniel Johnston, Jun 29 2011 *)

Mod[Prime[Range[100]], 4] (* Vincenzo Librandi, May 06 2014 *)