OFFSET
1,1
COMMENTS
It appears that a(n) = k such that binomial(prime(k),3) mod 2 = 1. See Maple code. - Gary Detlefs, Dec 06 2011
The above is correct (work mod 4). - Charles R Greathouse IV, Dec 06 2011
The asymptotic density of this sequence is 1/2 (by Dirichlet's theorem). - Amiram Eldar, Mar 01 2021
LINKS
Zak Seidov, Table of n, a(n) for n = 1..10000
FORMULA
MAPLE
pos_of_primes_k_mod_n(300, 3, 4); # Given in A080147.
A080148 := proc(n)
numtheory[pi](A002145(n)) ;
end proc:
seq(A080148(n), n=1..40) ; # R. J. Mathar, Dec 08 2011
MATHEMATICA
Flatten[Position[Prime[Range[200]], _?(IntegerQ[(#-3)/4]&)]] (* Harvey P. Dale, Jun 06 2011 *)
Select[Range[135], Mod[Prime[#], 4] == 3 &] (* Amiram Eldar, Mar 01 2021 *)
PROG
(PARI) i=0; forprime(p=2, 1e3, i++; if(p%4==3, print1(i", "))) \\ Charles R Greathouse IV, Dec 06 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 11 2003
STATUS
approved