A124186 Numbers n such that 1 + n + n^3 + n^5 + n^7 + n^9 + n^11 + ... + n^27 + n^29 + n^31 is prime.

1, 16, 25, 27, 93, 121, 187, 211, 267, 402, 420, 480, 601, 612, 631, 646, 667, 906, 916, 982, 1023, 1083, 1131, 1221, 1248, 1297, 1326, 1365, 1485, 1518, 1683, 1687, 1806, 1816, 1840, 1881, 1975, 1978, 2001, 2070, 2098, 2187, 2275, 2376, 2382, 2478, 2563, 2643, 2836, 3037, 3043

Offset

1,2

Comments

n can't be congruent to 2 mod 3, nor to 4 mod 5. - Robert Israel, Jun 24 2014

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

filter:= n -> isprime(1+add(n^(2*k+1), k=0..15));
select(filter, [$1..10000]); # Robert Israel, Jun 24 2014

Mathematica

Select[Range[100], PrimeQ[1 + Sum[#^(2k + 1), {k, 0, 15}]] &] (* Alonso del Arte, Jun 24 2014 *)
Select[Range[4000], PrimeQ[Total[#^Range[1, 31, 2]] + 1] &] (* Vincenzo Librandi, Jun 28 2014 *)

Prog

(PARI) for(n=1, 10^4, if(ispseudoprime(sum(i=0, 15, n^(2*i+1))+1), print1(n, ", "))) \\ Derek Orr, Jun 24 2014
(Magma) [n: n in [0..5000] | IsPrime(s) where s is 1+&+[n^i: i in [1..31 by 2]]]; // Vincenzo Librandi, Jun 28 2014
(Sage)
i, n = var('i, n')
[n for n in (1..3100) if is_prime(1+(n^(2*i+1)).sum(i, 0, 15))] # Bruno Berselli, Jun 28 2014

Crossrefs

Cf. A049407, similar sequences listed in A244376.

Sequence in context: A095409 A339624 A111026 * A274240 A176512 A001033

Adjacent sequences: A124183 A124184 A124185 * A124187 A124188 A124189

Keyword

nonn,easy

Author

Artur Jasinski, Dec 13 2006

Extensions

a(46)-a(51) from Derek Orr, Jun 24 2014

Status

approved