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A069272 11-almost primes (generalization of semiprimes). 29
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 (list; graph; refs; listen; history; text; internal format)
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

CROSSREFS

Sequences listing r-almost 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: A236373 A222526 A035892 * A234881 A220584 A195069

Adjacent sequences:  A069269 A069270 A069271 * A069273 A069274 A069275

KEYWORD

nonn

AUTHOR

Rick L. Shepherd, Mar 12 2002

STATUS

approved

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Last modified November 24 02:09 EST 2014. Contains 249867 sequences.