%I A040040
%S A040040 2,3,6,9,15,21,30,36,51,54,69,75,90,96,99,114,120,135,141,156,174,210,
%T A040040 216,231,261,285,300,309,321,330,405,411,414,429,441,510,516,525,531,
%U A040040 546,576,615,639,645,651,660,714,726,741,744,804,810,834,849,861,894
%N A040040 Average of twin prime pairs (A014574), divided by 2. Or, 2 a(n) +/- 1 
               are primes.
%C A040040 Intersection of A005097 and A006254. - Zak Seidov (zakseidov(AT)yahoo.com), 
               Mar 18 2005
%C A040040 The only possible pairs for 2a(n)+/-1 are prime/prime (this sequence), 
               not prime/not prime (A104278), prime/notprime (A104279) and not prime/
               prime (A104280), ... this sequence + A104280 + A104279 + A104278 
               = the odd numbers.
%H A040040 T. D. Noe, <a href="b040040.txt">Table of n, a(n) for n=1..10001</a>
%F A040040 a(n) = A014574(n)/2 = A054735(n+1)/4 = A111046(n+1)/8.
%p A040040 ZL:=[]:for p from 1 to 1800 do if (isprime(p) and isprime(p+2)) then 
               ZL:=[op(ZL),(((p+2)^2)-p^2)/8]; fi; od; print(ZL); - Zerinvary Lajos 
               (zerinvarylajos(AT)yahoo.com), Mar 08 2007
%t A040040 Select[Range[900], And @@ PrimeQ[{-1, 1} + 2# ] &] (*Chandler*)
%Y A040040 Cf. A001359, A006512, A014574, A054735, A111046.
%Y A040040 Sequence in context: A032231 A114323 A113808 this_sequence A086642 A014214 
               A094993
%Y A040040 Adjacent sequences: A040037 A040038 A040039 this_sequence A040041 A040042 
               A040043
%K A040040 nonn,easy
%O A040040 1,1
%A A040040 N. J. A. Sloane (njas(AT)research.att.com).
%E A040040 More terms from Cino Hilliard, Oct 21 2002
%E A040040 Title corrected by Daniel Forgues (squid(AT)zensearch.com), Jun 01 2009
%E A040040 Edited by Daniel Forgues (squid(AT)zensearch.com), Jun 21 2009
%E A040040 Comment corrected by Daniel Forgues (squid(AT)zensearch.com), Jul 12 
               2009