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Search: id:A134188
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| A134188 |
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a(0)=1. a(n) = the sum of the terms of the sequence (from among terms a(0) through a(n-1)) which equal any "non-isolated divisors" of (2n). A divisor, k, of n is non-isolated if (k-1) or (k+1) also divides n. |
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+0
2
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| 1, 1, 2, 4, 4, 4, 16, 4, 4, 4, 28, 4, 32, 4, 4, 4, 4, 4, 52, 4, 56, 4, 4, 4, 68, 4, 4, 4, 4, 4, 88, 4, 4, 4, 4, 4, 108, 4, 4, 4, 120, 4, 124, 4, 4, 4, 4, 4, 144, 4, 148, 4, 4, 4, 160, 4, 4, 4, 4, 4, 180, 4, 4, 4, 4, 4, 200, 4, 4, 4, 212, 4, 216, 4, 4, 4, 4, 4, 236, 4, 240, 4, 4, 4, 252, 4, 4, 4
(list; graph; listen)
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OFFSET
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0,3
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EXAMPLE
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The positive divisors of 2*12=24 are 1,2,3,4,6,8,12,24. Of these, 1,2,3,4 are the non-isolated divisors of 24. There are 2 terms among the earlier terms of the sequence that equal 1, 1 term that equals 2, 0 terms that equal 3, and 7 terms that equal 4. So a(12) = 2*1 +1*2 + 0*3 +7*4 = 32.
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CROSSREFS
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Cf. A134187.
Adjacent sequences: A134185 A134186 A134187 this_sequence A134189 A134190 A134191
Sequence in context: A082855 A107058 A101449 this_sequence A140295 A070529 A009145
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Oct 12 2007
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EXTENSIONS
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Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jun 25 2008
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