

A122123


Product of the first n 5almost primes (A014614).


1



32, 1536, 110592, 8847360, 955514880, 107017666560, 12842119987200, 2080423437926400, 349511137571635200, 61513960212607795200, 11072512838269403136000, 2214502567653880627200000, 460616534072007170457600000, 111929817779497742421196800000
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OFFSET

1,1


COMMENTS

5almost prime analog of primorial (A002110). The semiprime analog of primorial is A112141. Equivalent for product of what A086047 is for sum. Bigomega(a(n)) = the number of not necessarily distinct prime factors of a(n) = A001222(a(n)) = A008587(n) = 5*n.


LINKS

Table of n, a(n) for n=1..14.


FORMULA

a(n) = Prod[i=1..n] A014614(i).


EXAMPLE

a(10) = 32 * 48 * 72 * 80 * 108 * 112 * 120 * 162 * 168 * 176 = 2^33 * 3^12 * 5^2 * 7^2 * 11 which has 50 prime factors with multiplicity.


MATHEMATICA

Rest[FoldList[Times, 1, Select[Range[200], PrimeOmega[#]==5&]]] (* Harvey P. Dale, Feb 07 2012 *)


CROSSREFS

Cf. A001222, A002110, A008585, A014613, A008587, A086046, A086047, A112141, A114426.
Sequence in context: A301448 A220577 A200258 * A013994 A281953 A316181
Adjacent sequences: A122120 A122121 A122122 * A122124 A122125 A122126


KEYWORD

easy,nonn


AUTHOR

Jonathan Vos Post, Oct 19 2006


EXTENSIONS

More terms from Harvey P. Dale, Feb 07 2012


STATUS

approved



