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A267573 a(n) = prime(n) + (prime(n) mod 4). 1

%I #23 Sep 08 2022 08:46:15

%S 4,6,6,10,14,14,18,22,26,30,34,38,42,46,50,54,62,62,70,74,74,82,86,90,

%T 98,102,106,110,110,114,130,134,138,142,150,154,158,166,170,174,182,

%U 182,194,194,198,202,214,226,230,230,234,242,242,254,258,266,270

%N a(n) = prime(n) + (prime(n) mod 4).

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

%H Robert Israel, <a href="/A267573/b267573.txt">Table of n, a(n) for n = 1..10000</a>

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

%F a(n) = A083220(prime(n)). - _Michel Marcus_, Jan 17 2016

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

%p A267573:=n->ithprime(n)+(ithprime(n) mod 4): seq(A267573(n), n=1..100); # _Wesley Ivan Hurt_, Jan 17 2016

%t Table[Prime[n] + Mod[Prime[n], 4], {n, 60}] (* _Vincenzo Librandi_, Jan 17 2016 *)

%t #+Mod[#,4]&/@Prime[Range[60]] (* _Harvey P. Dale_, Jun 12 2020 *)

%o (Magma) [NthPrime(n)+(NthPrime(n) mod 4): n in [1..100]]; // _Vincenzo Librandi_, Jan 17 2016

%o (PARI) a(n) = prime(n) + (prime(n) % 4); \\ _Michel Marcus_, Jan 17 2016

%o (PARI) lista(nn) = forprime(p=2, nn, print1(p + p % 4, ", ")); \\ _Altug Alkan_, Jan 17 2016

%Y Cf. A000040, A039702, A071698, A083220.

%K nonn,easy

%O 1,1

%A _Emre APARI_, Jan 17 2016

%E More terms from _Vincenzo Librandi_, Jan 17 2016

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Last modified April 19 06:44 EDT 2024. Contains 371782 sequences. (Running on oeis4.)