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 A244379 Numbers k such that 1 + k + k^3 + k^5 + k^7 + k^9 + ... + k^21 is prime. 2

%I

%S 2,30,56,122,216,246,248,318,552,846,948,1100,1128,1148,1200,1296,

%T 1308,1416,1716,1812,1818,1920,2040,2166,2196,2210,2582,2592,2672,

%U 2696,2828,2862,2886,2970,3150,3192,3378,3396,3492,3522,3626,3782,3998,4040,4070

%N Numbers k such that 1 + k + k^3 + k^5 + k^7 + k^9 + ... + k^21 is prime.

%H Vincenzo Librandi, <a href="/A244379/b244379.txt">Table of n, a(n) for n = 1..700</a>

%t Select[Range[5000], PrimeQ[Total[#^Range[1, 21, 2]] + 1]&]

%o (Magma) [n: n in [0..4500] | IsPrime(s) where s is 1+&+[n^i: i in [1..21 by 2]]];

%o (Sage)

%o i,n = var('i,n')

%o [n for n in (1..4100) if is_prime(1+(n^(2*i+1)).sum(i,0,10))] # _Bruno Berselli_, Jun 27 2014

%Y Cf. similar sequences listed in A244376.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Jun 27 2014

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Last modified March 24 08:50 EDT 2023. Contains 361463 sequences. (Running on oeis4.)