|
%I #21 Sep 08 2022 08:45:28
%S 1,3,6,33,36,61,70,99,168,229,267,268,321,325,337,366,387,448,456,457,
%T 498,513,532,546,591,621,624,637,835,858,910,927,961,981,1045,1125,
%U 1213,1237,1242,1257,1341,1357,1437,1458,1461,1462,1482,1491,1572,1579,1581
%N Numbers n such that 1 + n + n^3 + n^5 + n^7 + n^9 + n^11 + n^13 + n^15 + n^17 + n^19 is prime.
%H Vincenzo Librandi, <a href="/A124178/b124178.txt">Table of n, a(n) for n = 1..1800</a>
%t Do[If[PrimeQ[1 + n + n^3 + n^5 + n^7 + n^9 + n^11 + n^13 + n^15 + n^17 + n^19], Print[n]], {n, 1, 1000}]
%t Select[Range[3000], PrimeQ[Total[#^Range[1, 19, 2]] + 1] &] (* _Vincenzo Librandi_, Jun 28 2014 *)
%o (Magma) [n: n in [0..2000] | IsPrime(1 +n +n^3 +n^5 +n^7 +n^9 +n^11 +n^13 +n^15 +n^17 +n^19)]; // _Vincenzo Librandi_, Nov 12 2010
%o (PARI) is(n)=n==1 || isprime((n^21-n)/(n^2-1)+1) \\ _Charles R Greathouse IV_, Jul 02 2013
%o (Magma) [n: n in [0..2000] | IsPrime(s) where s is 1+&+[n^i: i in [1..19 by 2]]]; // _Vincenzo Librandi_, Jun 28 2014
%o (Sage)
%o i,n = var('i,n')
%o [n for n in (1..2000) if is_prime(1+(n^(2*i+1)).sum(i,0,9))] # _Bruno Berselli_, Jun 28 2014
%Y Cf. A049407, similar sequences listed in A244376.
%K nonn,easy
%O 1,2
%A _Artur Jasinski_, Dec 13 2006
|
