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 A079078 a(0) = 1, a(1) = 2; for n>1, a(n) = p(n)*a(n-2) where p(n) is the n-th prime. 7
 1, 2, 3, 10, 21, 110, 273, 1870, 5187, 43010, 150423, 1333310, 5565651, 54665710, 239322993, 2569288370, 12684118629, 151588013830, 773731236369, 10156396926610, 54934917782199, 741416975642530, 4339858504793721 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Might be called the double primorial numbers and denoted by n##, by analogy with the double factorial numbers. LINKS EXAMPLE a(5)=110 because 2*5*11=110, the product of the first, third and fifth primes PROG (PARI) A079078(n)=prod(i=0, (n-1)\2, prime(n-2*i)) \\ - M. F. Hasler, May 04 2008 CROSSREFS Cf. A006882, A002110. Sequence in context: A161522 A120484 A113202 * A285794 A148056 A148057 Adjacent sequences:  A079075 A079076 A079077 * A079079 A079080 A079081 KEYWORD nonn AUTHOR Michael Joseph Halm, Feb 02 2003 EXTENSIONS Last term corrected by Jonathan Vos Post, Feb 09 2006 Edited and corrected by M. F. Hasler, May 06 2008 STATUS approved

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Last modified September 19 04:52 EDT 2019. Contains 327187 sequences. (Running on oeis4.)