OFFSET
1,1
COMMENTS
Numbers k such that Sum_{d|k} (-1)^d = A048272(k) = 2. - Benoit Cloitre, Apr 14 2002
LINKS
Paolo P. Lava, Table of n, a(n) for n = 1..20000
MATHEMATICA
4 * Prime[Range[66]] (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *)
PROG
(Haskell)
a001749 = (* 4) . a000040 -- Reinhard Zumkeller, Feb 20 2012
(PARI) a(n)=4*prime(n) \\ Charles R Greathouse IV, Mar 25 2014
(PARI) 4 * primes(66) \\ Joerg Arndt, Mar 26 2014
(Magma) [4*p: p in PrimesUpTo(300)]; // Vincenzo Librandi, Mar 26 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved