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%I #5 Dec 05 2013 19:56:52
%S 0,-5,19,713,2377,120637,259459177,1357170301,4929659569,
%T 42608389821509,11912739135894001,59907396092196739,
%U 20458385028296632427,7926428532945161230909,4693751193479184763610081,328774885640356760904499183363
%N (Product of composite numbers among next n numbers) - (product of primes among next n numbers).
%C Let c = product of composite numbers in the range [n(n-1)/2 + 1, n(n+1)/2], let p = product of prime numbers in the same range; then a(n) = c - p. Empty products = 1 by convention.
%e n = 1: no primes or composites hence 1-1= a(1)=0; n=2: range = 2 and 3, a(2)= (Product of composite numbers among next n numbers) - (product of primes among next n numbers) = empty product of composite numbers - 6 = 1-6 = -5; a(3)= 4*6 -5 as the next 3 numbers are (4,5,6).
%K sign,easy
%O 1,2
%A _Amarnath Murthy_, Jun 10 2004
%E More terms from _Joshua Zucker_, May 03 2006