A110853 - OEIS

%I #6 Jul 14 2012 11:40:53

%S 9,81,1089

%N Squares of the form prime(n)*(n+1)^2 + 1.

%C No further terms less than 4.89*10^24 (n=62662502). - Chandler

%e prime(1)*(1+1)^2+1= 2* 4+1= 9 = 3^2.

%e prime(3)*(3+1)^2+1= 5* 42+1= 81 = 9^2.

%e prime(7)*(7+1)^2+1=31*100+1=1089 =33^2.

%t Do[ s = Prime[n](n + 1)^2 + 1; If[ IntegerQ[ Sqrt[s]], Print[s]], {n, 5000000}] _Robert G. Wilson v_, Sep 26 2005

%K nonn,bref

%O 1,1

%A _Giovanni Teofilatto_, Sep 17 2005

%E Edited by _Ray Chandler_, Sep 26 2005