

A095218


(Product of composite numbers among next n numbers)  (product of primes among next n numbers).


0



0, 5, 19, 713, 2377, 120637, 259459177, 1357170301, 4929659569, 42608389821509, 11912739135894001, 59907396092196739, 20458385028296632427, 7926428532945161230909, 4693751193479184763610081, 328774885640356760904499183363
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OFFSET

1,2


COMMENTS

Let c = product of composite numbers in the range [n(n1)/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.


LINKS

Table of n, a(n) for n=1..16.


EXAMPLE

n = 1: no primes or composites hence 11= 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 = 16 = 5; a(3)= 4*6 5 as the next 3 numbers are (4,5,6).


CROSSREFS

Sequence in context: A122150 A092663 A072526 * A119964 A270477 A279256
Adjacent sequences: A095215 A095216 A095217 * A095219 A095220 A095221


KEYWORD

sign,easy


AUTHOR

Amarnath Murthy, Jun 10 2004


EXTENSIONS

More terms from Joshua Zucker, May 03 2006


STATUS

approved



