A095218 - OEIS

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A095218

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

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(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.

LINKS

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

EXAMPLE

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).

CROSSREFS

Sequence in context: A368888 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