A001749 Primes multiplied by 4.

8, 12, 20, 28, 44, 52, 68, 76, 92, 116, 124, 148, 164, 172, 188, 212, 236, 244, 268, 284, 292, 316, 332, 356, 388, 404, 412, 428, 436, 452, 508, 524, 548, 556, 596, 604, 628, 652, 668, 692, 716, 724, 764, 772, 788, 796, 844, 892, 908, 916, 932, 956, 964, 1004, 1028, 1052, 1076, 1084, 1108, 1124, 1132, 1172, 1228, 1244, 1252

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

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

Crossrefs

Cf. A000040, A003415, A048272.

Programs

Haskell

a001749 = (* 4) . a000040  -- Reinhard Zumkeller, Feb 20 2012

Magma

[4*p: p in PrimesUpTo(300)]; // Vincenzo Librandi, Mar 26 2014

Mathematica

4 * Prime[Range[66]] (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *)

PARI

a(n)=4*prime(n) \\ Charles R Greathouse IV, Mar 25 2014

PARI

4 * primes(66) \\ Joerg Arndt, Mar 26 2014