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Search: id:A109031
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| A109031 |
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11-almost primes (A069272) whose digit reversal is different and also has 11 prime factors (with multiplicity). "Emirp Tsolma-11.". |
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+0
4
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OFFSET
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1,1
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COMMENT
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This sequence is the k = 11 instance of the series which begins with k = 1 (emirps), k = 2 (emirpimes), k = 3 (emirp tsolma-3 = A109023), k = 4 (emirp tsolma-4 = A109024), k = 5 (emirp tsolma-5 = A109025), k = 6 (emirp tsolma-6 = A109026), k = 7 (emirp tsolma-7 = A109027), k = 8 (emirp tsolma-8 = A109028), k = 9 (emirp tsolma-9 = A109029), k = 10 (emirp tsolma-10 = A109030).
The Mma code for this was written by Ray Chandler who extended this sequence. He also has more values.
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REFERENCES
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Jonathan Vos Post, "1066 and All That: Emirp Tsolma-3 and Related Integer Sequences." Forthcoming paper on this sequence.
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LINKS
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Eric Weisstein's World of Mathematics, Almost Prime.
Eric Weisstein's World of Mathematics, Emirp.
Eric Weisstein and Jonathan Vos Post, Emirpimes.
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EXAMPLE
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a(1) = 295245 is in this sequence because 295245 = 3^10 * 5 is an 11-almost prime, and reverse(295245) = 542592 = 2^7 * 3^3 * 157 is also an 11-almost prime.
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CROSSREFS
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Cf. A069272, A006567, A097393, A109018, A109023-A109030.
Sequence in context: A104328 A050249 A023351 this_sequence A137817 A137818 A048906
Adjacent sequences: A109028 A109029 A109030 this_sequence A109032 A109033 A109034
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KEYWORD
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nonn,base
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AUTHOR
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Jonathan Vos Post (jvospost2(AT)yahoo.com), Jun 16 2005
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