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A100570
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Positive integers that cannot be partitioned as the sum of a semiprime and a square. Squares include 0 and 1.
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5
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1, 2, 3, 12, 17, 28, 32, 72, 108, 117, 297, 657
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| No others up to 300000. Computed in collaboration with Ray Chandler (rayjchandler(AT)sbcglobal.net). It appears that this sequence is finite, that is, that almost every positive integer is the sum of a semiprime and a square number. There are probably no more exceptions after a(12)=657.
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FORMULA
| a(n) is not an element for any integers i, j of the pairwise sum of {A001358(i)} and {A000290(j)}.
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CROSSREFS
| Cf. A000290, A001358, A046903.
Sequence in context: A046486 A073452 A112976 * A056700 A140989 A130089
Adjacent sequences: A100567 A100568 A100569 * A100571 A100572 A100573
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KEYWORD
| easy,nonn
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AUTHOR
| Jonathan Vos Post (jvospost3(AT)gmail.com), Nov 29 2004
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