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 A241289 Numbers n for which in the factorization of n! over distinct terms of A050376, the numbers of prime and nonprime terms are equal. 2
 7, 8, 9, 13, 18, 22, 37, 57, 71 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(10), if it exists, should be more than 5000. Is a(9)=71 the last term of sequence? - Peter J. C. Moses, Apr 19 2014 One can prove that a(9)=71 indeed is the last term of this sequence. - Vladimir Shevelev, Apr 19 2014. REFERENCES V. S. Shevelev, Multiplicative functions in the Fermi-Dirac arithmetic, Izvestia Vuzov of the North-Caucasus region, Nature sciences 4 (1996), 28-43 [Russian]. LINKS S. Litsyn and V. S. Shevelev, On factorization of integers with restrictions on the exponent, INTEGERS: Electronic Journal of Combinatorial Number Theory, 7 (2007), #A33, 1-36. EXAMPLE 7 is in the sequence, since 7! in the considered factorization is 5*7*9*16, and here we have 2 primes and 2 nonprimes. CROSSREFS Cf. A177329, A177333, A177334, A240537, A240606, A240619, A240620, A240668, A240669, A240670, A240672, A240695, A240751, A240755, A240764, A240905, A240906, A241123, A241124, A241139, A241148. Sequence in context: A297131 A289740 A289760 * A037369 A076599 A067197 Adjacent sequences:  A241286 A241287 A241288 * A241290 A241291 A241292 KEYWORD nonn,fini,full AUTHOR Vladimir Shevelev, Apr 18 2014 EXTENSIONS Terms a(7) - a(9) from Peter J. C. Moses, Apr 19 2014 STATUS approved

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Last modified April 17 05:12 EDT 2021. Contains 343059 sequences. (Running on oeis4.)