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A130770
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One third of the lowest common multiple of 3 and n^2+n+1.
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0
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1, 1, 7, 13, 7, 31, 43, 19, 73, 91, 37, 133, 157, 61, 211, 241, 91, 307, 343, 127, 421, 463, 169, 553, 601, 217, 703, 757, 271, 871, 931, 331, 1057, 1123, 397, 1261, 1333, 469, 1483, 1561, 547, 1723, 1807, 631, 1981, 2071, 721, 2257, 2353, 817, 2551, 2653, 919
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| This is a subset of A051176 and is also one third of A130723.
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FORMULA
| Conjecture: a(n)=A046163(n), n>0. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 13 2008
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EXAMPLE
| a(4)=7 because 4^2+4+1 =21, the LCM of 3 and 21 is 21 and 21/3=7.
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MAPLE
| seq(denom((n-1)^2/(n^2+n+1)), n=0..52) ; - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 04 2008
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CROSSREFS
| Cf. A051176, A130723.
Sequence in context: A164929 A081257 A046163 * A158622 A122874 A066003
Adjacent sequences: A130767 A130768 A130769 * A130771 A130772 A130773
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KEYWORD
| easy,nonn
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AUTHOR
| Neville Holmes (neville.holmes(AT)utas.edu.au), Jul 14 2007
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