A142183 - OEIS

%I #11 Sep 08 2022 08:45:35

%S 41,241,281,401,521,601,641,761,881,1201,1321,1361,1481,1601,1721,

%T 1801,2081,2161,2281,2441,2521,2801,3001,3041,3121,3361,3761,3881,

%U 4001,4201,4241,4441,4481,4561,4721,4801,5081,5281,5441,5521,5641,5801,5881,6121

%N Primes congruent to 1 mod 40.

%H Vincenzo Librandi, <a href="/A142183/b142183.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) ~ 16n log n. - _Charles R Greathouse IV_, Jul 03 2016

%t Select[Prime[Range[2000]],MemberQ[{1},Mod[#,40]]&] (* _Vincenzo Librandi_, Aug 20 2012 *)

%t Select[Range[1,7000,40],PrimeQ] (* _Harvey P. Dale_, Dec 07 2015 *)

%o (Magma)[p: p in PrimesUpTo(7000) | p mod 40 eq 1]; // _Vincenzo Librandi_, Aug 20 2012

%o (PARI) is(n)=isprime(n) && n%40==1 \\ _Charles R Greathouse IV_, Jul 03 2016

%Y Cf. A000040.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_, Jul 11 2008