# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a074766 Showing 1-1 of 1 %I A074766 #15 Mar 04 2017 13:51:42 %S A074766 -2,-1,0,1,2,5,2,7,6,3,6,3,6,7,4,9,4,11,10,11,14,13,10,21,10,11,18,21, %T A074766 24,25,8,17,10,25,16,21,22,19,24,23,22,29,18,27,24,35,22,9,18,33,40, %U A074766 39,42,37,32,31,24,41,34,37,46,35,24,33,42,43,28,27,24,41,44,37,32,37,30,39,32 %N A074766 a(n) = prime(2n) - 2*prime(n) - n. %C A074766 Conjecture: p(2n) - 2p(n) < 2n for all n. %F A074766 a(n) = A066066(n) - n. %e A074766 a(9) = p(18) - 2p(9) - 9 = 61 - 2*23 - 9 = 6. %p A074766 A074766:=n->ithprime(2*n)-2*ithprime(n)-n: seq(A074766(n), n=1..100); # _Wesley Ivan Hurt_, Jan 16 2017 %t A074766 Table[Prime[2 n] - 2 Prime[n] - n, {n, 80}] (* _Harvey P. Dale_, Mar 04 2017 *) %Y A074766 Cf. A066066. %K A074766 sign %O A074766 1,1 %A A074766 _Werner D. Sand_, Sep 29 2002 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE