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%I #8 Aug 11 2014 22:45:44
%S 2,5,7,11,19,23,29,41,47,71,79,89,109,131,167,181,223,239,271,359,379,
%T 419,439,461,599,701,727,811,839,929,991,1087,1223,1259,1367,1481,
%U 1559,1721,1847,1979,2069,2161,2207,2351,2399,2549,2861,2969,3023,3079,3191
%N Primes in A179272.
%C Primes of form floor(((n^2)/4) - (n/2) - 1). Primes in sharp upper bound on Rosgen overlap number n-vertex graph with n => 14, formula abused here for nonnegative integers. There seem to be more primes (29) through n = 60 of floor(((n^2)/4) - (n/2) - 1) than one might expect. What fraction through n = 1000 are prime?
%H Harvey P. Dale, <a href="/A179273/b179273.txt">Table of n, a(n) for n = 1..1000</a>
%H Daniel W. Cranston, Nitish Korula, Timothy D. LeSaulnier, Kevin Milans, Christopher Stocker, Jennifer Vandenbussche, Douglas B. West, <a href="http://arxiv.org/abs/1007.0804">Overlap Number of Graphs</a>, Jul 06, 2010.
%e a(1) = floor(((5^2)/4) - (5/2) - 1) = floor(16/4 - 5/2 - 1) = floor(11/4) = 2.
%e a(2) = floor(((6^2)/4) - (6/2) - 1) = floor(36/4 - 6/2 - 1) = floor(5) = 5.
%t Select[Table[Floor[n^2/4-n/2-1],{n,5,200}],PrimeQ] (* _Harvey P. Dale_, Oct 12 2012 *)
%Y Cf. A000040, A179272.
%K easy,nonn
%O 1,1
%A _Jonathan Vos Post_, Jul 07 2010
%E More terms from _R. J. Mathar_, Oct 15 2010
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