A267573 a(n) = prime(n) + (prime(n) mod 4).

4, 6, 6, 10, 14, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 62, 62, 70, 74, 74, 82, 86, 90, 98, 102, 106, 110, 110, 114, 130, 134, 138, 142, 150, 154, 158, 166, 170, 174, 182, 182, 194, 194, 198, 202, 214, 226, 230, 230, 234, 242, 242, 254, 258, 266, 270

Offset: 1

Author

Emre APARI, Jan 17 2016

Keywords

• nonn
• easy

Comments

The primes corresponding to the cases where a(n) = a(n+1) can be found in A071698. - Michel Marcus, Jan 17 2016

Examples

			p=19; 19 + (19 modulo 4) = 22.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A039702, A071698, A083220.

Programs

Magma

[NthPrime(n)+(NthPrime(n) mod 4): n in [1..100]]; // Vincenzo Librandi, Jan 17 2016

Maple

A267573:=n->ithprime(n)+(ithprime(n) mod 4): seq(A267573(n), n=1..100); # Wesley Ivan Hurt, Jan 17 2016

Mathematica

Table[Prime[n] + Mod[Prime[n], 4], {n, 60}] (* Vincenzo Librandi, Jan 17 2016 *)
#+Mod[#,4]&/@Prime[Range[60]] (* Harvey P. Dale, Jun 12 2020 *)

PARI

a(n) = prime(n) + (prime(n) % 4); \\ Michel Marcus, Jan 17 2016

PARI

lista(nn) = forprime(p=2, nn, print1(p + p % 4, ", ")); \\ Altug Alkan, Jan 17 2016

Formula

a(n) = A000040(n) + A039702(n).

a(n) = A083220(prime(n)). - Michel Marcus, Jan 17 2016

Extensions

More terms from Vincenzo Librandi, Jan 17 2016