A139512: Mod[a(n),12]=1

[Artur]

Thanks Zak! That mean that  A139512 
<http://www.research.att.com/%7Enjas/sequences/A068228> is subset of 
A068228 <http://www.research.att.com/%7Enjas/sequences/A068228>
But many primes of the form 12n+1 don't have representation by symmetric 
form x^2+32xy+y^2
Artur

zak seidov pisze:
> Are all terms a(n) == 1 (mod 12)?
>
> thanks, zak
>
> %I A139512 %S A139512
> 229,349,409,421,661,769,829,1021,1069,1249,1381,1429,1549,1789,1801,
> 1861,2089,2161,2269,2389,3001,3061,3109,3181,3229,3469,3889,4021,4129,
>
> 4201,4441,4861,4909,5101,5449,5521,5869,5881,6121,6469,6481,6529,6781
>
> %N A139512 Primes of the form x^2+32x*y+y^2. %t
> A139512 a = {}; w = 32; k = 1; Do[Do[If[PrimeQ[n^2 +
> w*n*m + k*m^2], AppendTo[a, n^2 + w*n*m + k*m^2]], {n,
> m, 400}], {m, 1, 400}]; Union[a] (*Artur Jasinski*) %Y
> A139512 Cf. A139489, A007645, A068228, A007519,
> A033212, A033212, A107152, A107008, A033215, A107145,
> A139490, A139491. %K A139512 nonn,new %O A139512 1,1
> %A A139512 Artur Jasinski (grafix(AT)csl.pl), Apr 24
> 2008 
>
>
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