A075521 Primes p such that 4*p + (p mod 4) is also a prime.

7, 11, 13, 19, 31, 37, 47, 59, 67, 73, 97, 107, 151, 179, 193, 227, 271, 277, 307, 331, 359, 367, 373, 409, 433, 439, 467, 487, 499, 571, 577, 587, 599, 647, 673, 691, 709, 719, 839, 853, 907, 991, 997, 1019, 1031, 1033, 1039, 1093, 1129, 1187, 1259, 1279

Offset: 1

Author

Reinhard Zumkeller, Sep 19 2002

Keywords

• nonn

Comments

A075522(a(n)) > 1.

A010051(A075520(A049084(a(n)))) = 1. [Reinhard Zumkeller, Feb 20 2012]

Examples

			11 is a term as 4*11+(11 mod 4) = 44+3 = 47 is prime.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Programs

Haskell

a075521 n = a075521_list !! (n-1)
a075521_list = map a000040 $ filter ((== 1) . a010051' . a075520) [1..]
-- Reinhard Zumkeller, Feb 20 2012

Mathematica

Select[Prime[Range[300]], PrimeQ[4*# + Mod[#, 4]] &] (* Vladimir Joseph Stephan Orlovsky, Feb 17 2012 *)