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A152745
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5 times hexagonal numbers: 5*n*(2*n-1).
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4
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0, 5, 30, 75, 140, 225, 330, 455, 600, 765, 950, 1155, 1380, 1625, 1890, 2175, 2480, 2805, 3150, 3515, 3900, 4305, 4730, 5175, 5640, 6125, 6630, 7155, 7700, 8265, 8850, 9455, 10080, 10725, 11390, 12075, 12780, 13505, 14250, 15015
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Sequence found by reading the line from 0, in the direction 0, 5,..., in the square spiral whose vertices are the generalized heptagonal numbers A085787. - Omar E. Pol, Sep 18 2011
Also sequence found by reading the line from 0, in the direction 0, 5,..., in the square spiral whose edges have length A195013 and whose vertices are the numbers A195014. This is one of the four semi-diagonals of the spiral. - Omar E. Pol, Oct 14 2011
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FORMULA
| a(n) = 10*n^2 - 5*n = A000384(n)*5.
a(n)=a(n-1)+20*n-15 (with a(0)=0) [From Vincenzo Librandi, Nov 26 2010]
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MATHEMATICA
| s=0; lst={s}; Do[s+=n; AppendTo[lst, s], {n, 5, 8!, 20}]; lst [From Vladimir Orlovsky, Apr 03 2009]
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CROSSREFS
| Cf. A000384, A085250, A152746.
Bisection of A028895. - Omar E. Pol, Oct 14 2011
Sequence in context: A206329 A043886 A044463 * A187275 A164015 A128302
Adjacent sequences: A152742 A152743 A152744 * A152746 A152747 A152748
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KEYWORD
| easy,nonn
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Dec 12 2008
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