

A069276


15almost primes (generalization of semiprimes).


29



32768, 49152, 73728, 81920, 110592, 114688, 122880, 165888, 172032, 180224, 184320, 204800, 212992, 248832, 258048, 270336, 276480, 278528, 286720, 307200, 311296, 319488, 373248, 376832, 387072, 401408, 405504, 414720, 417792, 430080
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OFFSET

1,1


COMMENTS

Product of 15 not necessarily distinct primes.
Divisible by exactly 15 prime powers (not including 1).
Any 15almost prime can be represented in several ways as a product of three 5almost primes A014614, and in several ways as a product of five 3almost primes A014612.  Jonathan Vos Post, Dec 11 2004


LINKS



FORMULA

Product p_i^e_i with Sum e_i = 15.


MATHEMATICA

Select[Range[450000], PrimeOmega[#]==15&] (* Harvey P. Dale, Aug 14 2019 *)


PROG

(PARI) k=15; start=2^k; finish=500000; v=[] for(n=start, finish, if(bigomega(n)==k, v=concat(v, n))); v


CROSSREFS

Sequences listing ralmost primes, that is, the n such that A001222(n) = r: A000040 (r = 1), A001358 (r = 2), A014612 (r = 3), A014613 (r = 4), A014614 (r = 5), A046306 (r = 6), A046308 (r = 7), A046310 (r = 8), A046312 (r = 9), A046314 (r = 10), A069272 (r = 11), A069273 (r = 12), A069274 (r = 13), A069275 (r = 14), this sequence (r = 15), A069277 (r = 16), A069278 (r = 17), A069279 (r = 18), A069280 (r = 19), A069281 (r = 20).  Jason Kimberley, Oct 02 2011


KEYWORD

nonn


AUTHOR



STATUS

approved



