login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A268859 Prime numbers ending in 21. 3

%I

%S 421,521,821,1021,1321,1621,1721,2221,2521,2621,3121,3221,3821,4021,

%T 4421,4621,4721,5021,5521,5821,6121,6221,6421,6521,7121,7321,7621,

%U 8221,8521,8821,9221,9421,9521,9721,10321,11321,11621,11821,12421,12721,12821,13121

%N Prime numbers ending in 21.

%p A268859:=n->`if`(isprime(n) and n mod 100 = 21, n, NULL): seq(A268859(n), n=1..5*10^4); # _Wesley Ivan Hurt_, Apr 02 2016

%t Select[Table[21 + 100 i, {i, 0, 10^3}], ProvablePrimeQ[#] &]

%o (MAGMA) [n: n in PrimesUpTo(15000) | n mod 100 eq 21]; // _Vincenzo Librandi_, Feb 15 2016

%o (PARI) lista(nn) = {for(n=1, nn, if (isprime(p=100*n+21), print1(p, ", ")););} \\ _Michel Marcus_, Feb 20 2016

%o (Python)

%o from sympy import isprime

%o for n in range(421,15000,100):

%o if(isprime(n)):print(n)

%o # _Soumil Mandal_, Apr 03 2016

%Y Cf. A268858, A268860.

%K nonn,base

%O 1,1

%A _Soumadeep Ghosh_, Feb 14 2016

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 1 07:40 EDT 2020. Contains 334759 sequences. (Running on oeis4.)