%I A002327 M3810 N1558
%S A002327 5,11,19,29,41,71,89,109,131,181,239,271,379,419,461,599,701,811,929,
%T A002327 991,1259,1481,1559,1721,1979,2069,2161,2351,2549,2861,2969,3079,3191,
%U A002327 3539,3659,4159,4289,4421,4691,4969,5851,6971,7309,7481,8009,8741,8929
%N A002327 Primes of form n^2 - n - 1.
%C A002327 Also primes of form x*y + x + y or x*y - x - y, where x and y are two 
               successive numbers. - Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), 
               May 12 2004
%C A002327 Equivalently primes p such that 4p+5 is square. - Giovanni Teofilatto 
               (g.teofilatto(AT)tiscalinet.it), Sep 03 2005
%C A002327 Arithmetic numbers which are triangular, A003601(p)=A000217(k), p prime. 
               sigma_1(p)/sigma_0(p)= k*(k+1)/2; sigma_r(p) divisor function, p 
               prime, k integer. - Ctibor O. Zizka (ctibor.zizka(AT)seznam.cz), 
               Jul 14 2008
%D A002327 D. H. Lehmer, Guide to Tables in the Theory of Numbers. Bulletin No. 
               105, National Research Council, Washington, DC, 1941, p. 46.
%D A002327 L. Poletti, Tavole di Numeri Primi Entro Limiti Diversi e Tavole Affini, 
               Milan, 1920, p. 249.
%D A002327 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A002327 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%F A002327 a(n) = A002328(n)^2 - A002328(n) - 1 = (A110013(n) - 5)/4. - Chandler
%t A002327 a={};Do[p=n^2-n-1;If[PrimeQ[p],AppendTo[a,p]],{n,10^2}];Print[a]; - Vladimir 
               Orlovsky (4vladimir(AT)gmail.com), Apr 29 2008
%Y A002327 Cf. A002328, A088502, A110013.
%Y A002327 Cf. A003601, AA000217.
%Y A002327 Sequence in context: A106071 A073847 A024833 this_sequence A078179 A045451 
               A100920
%Y A002327 Adjacent sequences: A002324 A002325 A002326 this_sequence A002328 A002329 
               A002330
%K A002327 nonn,easy
%O A002327 1,1
%A A002327 N. J. A. Sloane (njas(AT)research.att.com).
%E A002327 Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Sep 07 2005