A122565 Twin primes of form 4k+1, 4k+3.

5, 7, 17, 19, 29, 31, 41, 43, 101, 103, 137, 139, 149, 151, 197, 199, 269, 271, 281, 283, 461, 463, 521, 523, 569, 571, 617, 619, 641, 643, 809, 811, 821, 823, 857, 859, 881, 883, 1049, 1051, 1061, 1063, 1229, 1231, 1277, 1279, 1289, 1291, 1301, 1303, 1481

Offset: 1

Author

Miklos Kristof, Sep 21 2006

Keywords

• nonn

Comments

Twin primes with Hamming distance 1 between them. - Vladimir Shevelev, Jan 29 2012

Examples

			a(3) = 17 = 4*4 + 1, a(4) = 19 = 4*4 + 3.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001097, A123986, A205649.

Programs

Maple

i:=1:for k from 1 to 600 do if isprime(4*k+1) and isprime(4*k+3) then a[i]:=4*k+1:a[i+1]:=4*k+3: i:=i+2 fi od: seq(a[n],n=1..i-1);

Mathematica

Flatten[Select[Table[4k+{1,3},{k,400}],And@@PrimeQ[#] &]] (* Jayanta Basu, May 26 2013 *)