The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A181283 Numbers n with property that (n+1)*prime(n+1)-n*prime(n) is a perfect square s^2. 0

%I

%S 1,2,24,45,58,64,135,168,287,325,455,601,1506,1965,1990,2070,2189,

%T 2428,3967,4017,4388,4895,6966,7419,9252,10144,10242,10618,12980,

%U 14175,14385,14740,15140,18724,22424,24203,24935,24989,25171,25974,27817,29688

%N Numbers n with property that (n+1)*prime(n+1)-n*prime(n) is a perfect square s^2.

%F {n,s}:{1,2},{2,3},{24,17},{45,17},{58,25},{64,21},{135,43},{168,55},{287,55}.

%t Select[Range[30000],IntegerQ[Sqrt[(#+1)Prime[#+1]-# Prime[#]]]&] (* _Harvey P. Dale_, Mar 20 2012 *)

%o (PARI) a=2;{for(n=1,10^5,b=nextprime(a+1);issquare((n+1)*b-n*a)&print(n);a=b)}

%Y Cf. A175897.

%K nonn

%O 1,2

%A _Zak Seidov_, Oct 12 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 26 05:00 EDT 2020. Contains 337346 sequences. (Running on oeis4.)