Search: id:A002973 Results 1-1 of 1 results found. %I A002973 M0135 %S A002973 1,1,2,1,3,2,1,3,4,4,2,5,5,4,2,5,3,1,5,6,7,1,4,2,8,5,7,8,1,6,7,8,9,4,9, %T A002973 5,3,10,10,7,6,10,2,5,11,10,5,7,10,12,4,12,9,8,2,11,3,6,13,13,11,1,13, %U A002973 10,6,11,13,14,7,5,9,2,3,8,10,12,5,14,2,3,14,11,15,16,16,5,15,1,8,11 %N A002973 a(n) is half of the even member of {x,y}, where x^2+y^2 is the n-th prime of the form 4i+1. %C A002973 a(n) is odd iff x^2+y^2==5(mod 8). [From Vladimir Shevelev (shevelev(AT)bgu.ac.il), Jul 12 2009] %D A002973 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A002973 E. Kogbetliantz and A. Krikorian, Handbook of First Complex Prime Numbers, Gordon and Breach, NY, 1971, p. 243. %H A002973 T. D. Noe, Table of n, a(n) for n=1..1000 %H A002973 S. R. Finch, Powers of Euler's q-Series, (arXiv:math.NT/0701251). %e A002973 The 3rd prime of the form 4i+1 is 17=1^2+4^2, so a(3)=4/2=2. %Y A002973 Cf. A002144, A002972. %Y A002973 Sequence in context: A115624 A076291 A124458 this_sequence A071476 A071499 A039953 %Y A002973 Adjacent sequences: A002970 A002971 A002972 this_sequence A002974 A002975 A002976 %K A002973 nonn %O A002973 1,3 %A A002973 N. J. A. Sloane (njas(AT)research.att.com). %E A002973 Better description from Jud McCranie (j.mccranie(AT)comcast.net), Mar 05 2003 Search completed in 0.001 seconds