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 A141219 Write the n-th nonprime (A018252(n)) as a product of primes; increase one copy of the largest prime by 1 and decrease one copy of the smallest prime by 1, multiply the resulting numbers. 3
 1, 3, 4, 6, 8, 6, 8, 8, 12, 12, 12, 12, 16, 12, 16, 24, 14, 24, 16, 18, 24, 24, 18, 32, 24, 20, 28, 24, 24, 24, 36, 24, 32, 48, 30, 36, 28, 36, 48, 32, 40, 30, 36, 32, 48, 48, 56, 36, 36, 48, 40, 48, 38, 60, 40, 72, 42, 48, 72, 42, 48, 72, 44, 60, 48, 54, 84 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE 1st nonprime = 1 (has no prime factors); a(1) = empty product = 1. 2nd nonprime = 4 = (p(max)=2)*(p(min)=2); a(2) = (2+1)*(2-1) = 3*1 = 3. 3rd nonprime = 6 = (p(max)=3)*(p(min)=2); a(3) = (3+1)*(2-1) = 4*1 = 4. 4th nonprime = 8 = (p(max)=2)*(p=2)*(p(min)=2); a(4) = (2+1)*2*(2-1) = 3*2*1 = 6. CROSSREFS Sequence in context: A290115 A225794 A206769 * A069211 A242822 A295996 Adjacent sequences:  A141216 A141217 A141218 * A141220 A141221 A141222 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Aug 07 2008 EXTENSIONS Three terms corrected by R. J. Mathar, Aug 18 2008 Entry revised by Jon E. Schoenfield, Mar 09 2014, following revision of A141218 by N. J. A. Sloane STATUS approved

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Last modified July 26 14:45 EDT 2021. Contains 346294 sequences. (Running on oeis4.)