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0, 13, 32, 57, 88, 125, 168, 217, 272, 333, 400, 473, 552, 637, 728, 825, 928, 1037, 1152, 1273, 1400, 1533, 1672, 1817, 1968, 2125, 2288, 2457, 2632, 2813, 3000, 3193, 3392, 3597, 3808, 4025, 4248, 4477, 4712, 4953, 5200, 5453, 5712
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(n)=3*n^2 + 10*n.
a(n)=6*n+a(n-1)+7 (with a(0)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 03 2010]
G.f.: x*(13 - 7*x)/(1 - x)^3. [Arkadiusz Wesolowski, Dec 24 2011]
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EXAMPLE
| a(1)=6*1+0+7=13; a(2)=6*2+13+7=32; a(3)=6*3+32+7=57 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 03 2010]
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MATHEMATICA
| s=0; lst={s}; Do[s+=n++ +13; AppendTo[lst, s], {n, 0, 7!, 6}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 19 2008]
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CROSSREFS
| Cf. A033428, A045944, A140676, A067725, A140677, A067707, A140679, A140680, A140681, A140689.
Sequence in context: A159670 A087511 A118513 * A206345 A050659 A123161
Adjacent sequences: A140675 A140676 A140677 * A140679 A140680 A140681
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KEYWORD
| easy,nonn
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), May 22 2008
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