|
%I #4 Jun 12 2014 17:43:03
%S 8,27,729,1728,27000,185193,287496,658503,1367631,1728000,7414875,
%T 14348907,14886936,21717639,54010152,55306341,80621568,91125000,
%U 104487111,110592000,212776173,275894451,437245479,531441000,812166237
%N Cubes c(n) such that cube(n)-square(n)-1 and cube(n)+square(n)+1 are primes.
%C 2^3-2^2-1=3;2^3+2^2+1=13, 3^3-3^2-1=17;3^3+3^2+1=37, ...
%H Harvey P. Dale, <a href="/A155930/b155930.txt">Table of n, a(n) for n = 1..1000</a>
%t lst={};Do[c=n^3;s=n^2;p1=c-s-1;p2=c+s+1;If[PrimeQ[p1]&&PrimeQ[p2],AppendTo[lst,c]],{n,7!}];lst
%t cspQ[n_]:=Module[{x3=n^3,x2=n^2},And@@PrimeQ[{x3-x2-1,x3+x2+1}]]; Select[ Range[ 1000],cspQ]^3 (* _Harvey P. Dale_, Jun 12 2014 *)
%Y Cf. A155929
%K nonn
%O 1,1
%A _Vladimir Joseph Stephan Orlovsky_, Jan 30 2009
|
