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Search: id:A123321
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| A123321 |
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Products of 7 distinct primes (square-free 7-almost primes). |
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+0
3
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| 510510, 570570, 690690, 746130, 870870, 881790, 903210, 930930, 1009470, 1067430, 1111110, 1138830, 1193010, 1217370, 1231230, 1272810, 1291290, 1345890, 1360590, 1385670, 1411410, 1438710, 1452990, 1504230, 1540770
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Intersection of A005117 and A046308.
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LINKS
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Rick L. Shepherd, Table of n, a(n) for n = 1..10000
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EXAMPLE
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a(1) = 510510 = 2*3*5*7*11*13*17 = A002110(7).
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MATHEMATICA
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f7Q[n_]:=Last/@FactorInteger[n]=={1, 1, 1, 1, 1, 1, 1}; lst={}; Do[If[f7Q[n], AppendTo[lst, n]], {n, 9!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 26 2008]
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CROSSREFS
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Cf. A005117, A046308, A048692, Square-free k-almost primes: A000040 (k=1), A006881 (k=2), A007304 (k=3), A046386 (k=4), A046387 (k=5), A067885 (k=6), A123322 (k=8), A115343 (k=9).
Sequence in context: A124945 A076337 A101036 this_sequence A147574 A046325 A136352
Adjacent sequences: A123318 A123319 A123320 this_sequence A123322 A123323 A123324
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KEYWORD
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nonn
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AUTHOR
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Rick L. Shepherd (rshepherd2(AT)hotmail.com), Sep 25 2006
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EXTENSIONS
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More terms from Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 26 2008
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