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A256776 Primes of form n^2 + 256. 14

%I

%S 257,281,337,617,881,1097,1217,1481,1777,2281,2657,2857,4481,5297,

%T 5881,7481,8537,9281,10457,12577,14897,15881,17417,18481,19577,23057,

%U 24281,25537,26177,27481,28817,30881,32297,35977,38281,39857,42281,44777,52697,53617

%N Primes of form n^2 + 256.

%C Conjecture: sequence is infinite.

%H Reinhard Zumkeller, <a href="/A256776/b256776.txt">Table of n, a(n) for n = 1..10000</a>

%o (Haskell)

%o a256776 n = a256776_list !! (n-1)

%o a256776_list = [x | x <- map (+ 256) a000290_list, a010051' x == 1]

%o (PARI) list(lim)=if(lim<257,return([])); my(v=List(),t); forstep(n=1, sqrtint(lim\1-256), 2, if(isprime(t=n^2+256), listput(v,t))); Vec(v) \\ _Charles R Greathouse IV_, Aug 18 2017

%Y Cf. A010051, A000290; subsequence of A028916.

%Y Primes of form n^2+b^4, b fixed: A002496 (b=1), A243451 (b=2), A256775 (b=3), A256777 (b=5), A256834 (b=6), A256835 (b=7), A256836 (b=8), A256837 (b=9), A256838 (b=10), A256839 (b=11), A256840 (b=12), A256841 (b=13).

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Apr 11 2015

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Last modified August 18 13:28 EDT 2018. Contains 313832 sequences. (Running on oeis4.)