

A069272


11almost primes (generalization of semiprimes).


34



2048, 3072, 4608, 5120, 6912, 7168, 7680, 10368, 10752, 11264, 11520, 12800, 13312, 15552, 16128, 16896, 17280, 17408, 17920, 19200, 19456, 19968, 23328, 23552, 24192, 25088, 25344, 25920, 26112, 26880, 28160, 28800, 29184, 29696
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OFFSET

1,1


COMMENTS

Product of 11 not necessarily distinct primes.
Divisible by exactly 11 prime powers (not including 1).


LINKS

D. W. Wilson, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Almost Prime.


FORMULA

Product p_i^e_i with Sum e_i = 11.
a(n) ~ 3628800n log n / (log log n)^10.  Charles R Greathouse IV, May 06 2013


MATHEMATICA

Select[Range[9000], Plus @@ Last /@ FactorInteger[ # ] == 11 &] (* Vladimir Joseph Stephan Orlovsky, Apr 23 2008 *)
Select[Range[30000], PrimeOmega[#]==11&] (* Harvey P. Dale, Jul 13 2013 *)


PROG

(PARI) k=11; start=2^k; finish=30000; v=[] for(n=start, finish, if(bigomega(n)==k, v=concat(v, n))); v
(PARI) is(n)=bigomega(n)==11 \\ Charles R Greathouse IV, Oct 15 2015


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), this sequence (r = 11), A069273 (r = 12), A069274 (r = 13), A069275 (r = 14), A069276 (r = 15), A069277 (r = 16), A069278 (r = 17), A069279 (r = 18), A069280 (r = 19), A069281 (r = 20).  Jason Kimberley, Oct 02 2011
Sequence in context: A353409 A222526 A035892 * A234881 A220584 A195069
Adjacent sequences: A069269 A069270 A069271 * A069273 A069274 A069275


KEYWORD

nonn


AUTHOR

Rick L. Shepherd, Mar 12 2002


STATUS

approved



