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A069280
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19-almost primes (generalization of semiprimes).
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28
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524288, 786432, 1179648, 1310720, 1769472, 1835008, 1966080, 2654208, 2752512, 2883584, 2949120, 3276800, 3407872, 3981312, 4128768, 4325376, 4423680, 4456448, 4587520, 4915200, 4980736, 5111808, 5971968, 6029312, 6193152
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OFFSET
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1,1
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COMMENTS
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Product of 19 not necessarily distinct primes.
Divisible by exactly 19 prime powers (not including 1).
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LINKS
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D. W. Wilson, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Almost Prime.
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FORMULA
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Product p_i^e_i with Sum e_i = 19.
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PROG
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(PARI) k=19; start=2^k; finish=8000000; v=[] for(n=start, finish, if(bigomega(n)==k, v=concat(v, n))); v
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CROSSREFS
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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), A069272 (r = 11), A069273 (r = 12), A069274 (r = 13), A069275 (r = 14), A069276 (r = 15), A069277 (r = 16), A069278 (r = 17), A069279 (r = 18), this sequence (r = 19), A069281 (r = 20). - Jason Kimberley, Oct 02 2011
Sequence in context: A069394 A289480 A222530 * A017702 A010807 A236227
Adjacent sequences: A069277 A069278 A069279 * A069281 A069282 A069283
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KEYWORD
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nonn
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AUTHOR
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Rick L. Shepherd, Mar 13 2002
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STATUS
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approved
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