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 A131690 a(n) = Product prime1(k)^prime1(n-k+1), k = 1 to n. 0
 1, 2, 12, 360, 151200, 2095632000, 7551819475200000, 7286477990937425280000000, 16326289449604557795871699200000000000, 48235535472088469901966394717904245153920000000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Exponents of the prime factorization are the primes in reverse order. Similar to A087315, but where the largest prime factor has an exponent of one instead of two (and 1^n is understood to be the first term). LINKS FORMULA a(n) = Product prime1(k)^prime1(n-k+1), k = 1 to n, where prime1 is the sequence of primes prepended with 1. EXAMPLE a(5) = 1^7 * 2^5 * 3^3 * 5^2 * 7^1 = 151200 CROSSREFS Cf. A087315, A076265, A076265. Sequence in context: A079264 A006939 A152686 * A158261 A215956 A251182 Adjacent sequences:  A131687 A131688 A131689 * A131691 A131692 A131693 KEYWORD nonn AUTHOR Darse Billings, Sep 14 2007 STATUS approved

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Last modified June 29 18:25 EDT 2022. Contains 354913 sequences. (Running on oeis4.)