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Search: id:A166155
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| A166155 |
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Numbers n such that number of divisors of n + number of perfect partitions of (n-1) = prime. |
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+0
1
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| 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, 22, 23, 25, 26, 29, 31, 33, 34, 35, 37, 38, 39, 41, 43, 46, 47, 49, 51, 53, 55, 57, 58, 59, 61, 62, 65, 67, 69, 71, 73, 74, 77, 79, 81, 82, 83, 85, 86, 87, 89, 91, 93, 94, 95, 97, 101, 103, 106, 107, 109, 111, 113, 115, 118, 119
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Or, numbers n such that A000005(n)+A002033(n-1)=prime.
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EXAMPLE
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If n=1 and A000005(1)+A002033(0)=1+1=2(prime), then a(1)=1. If n=2 and A000005(2)+A002033(1)=2+1=3(prime), then a(2)=2. If n=3 and A000005(3)+A002033(2)=2+1=3(prime), then a(3)=3. If n=4 and A000005(4)+A002033(3)=3+2=5(prime), then a(4)=4. If n=5 and A000005(5)+A002033(4)=2+1=3(prime), then a(5)=5. If n=6 and A000005(6)+A002033(5)=4+3=7(prime), then a(6)=6. If n=7 and A000005(7)+A002033(6)=2+1=3(prime), then a(7)=7. If n=8, then A000005(8)+A002033(7)=4+4=8=nonprime. If n=9 and A000005(9)+A002033(8)=3+2=5(prime), then a(8)=8.
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CROSSREFS
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Cf. A000005, A000027, A000040, A002033.
Sequence in context: A072497 A039217 A131511 this_sequence A063538 A167207 A037143
Adjacent sequences: A166152 A166153 A166154 this_sequence A166156 A166157 A166158
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KEYWORD
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nonn
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AUTHOR
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Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Oct 08 2009
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EXTENSIONS
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Definition and examples corrected, duplicate of 49 removed, 64 removed - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 09 2009
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