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0, 12, 25, 39, 54, 70, 87, 105, 124, 144, 165, 187, 210, 234, 259, 285, 312, 340, 369, 399, 430, 462, 495, 529, 564, 600, 637, 675, 714, 754, 795, 837, 880, 924, 969, 1015, 1062, 1110, 1159, 1209, 1260, 1312, 1365, 1419, 1474, 1530
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(n) = n*(n+23)/2.
If we define f(n,i,a)=sum(binomial(n,k)*stirling1(n-k,i)*product(-a-j,j=0..k-1),k=0..n-i), then a(n) = -f(n,n-1,12), for n>=1. [From Milan R. Janjic (agnus(AT)blic.net), Dec 20 2008]
a(n)=n+a(n-1)+11 (with a(0)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 03 2010]
a(0)=0, a(1)=12, a(2)=25, a(n)=3*a(n-1)-3*a(n-2)+a(n-3) [From Harvey P. Dale, June 21 2011]
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EXAMPLE
| a(1)=1+0+11=12; a(2)=2+12+11=25; a(3)=3+25+11=39 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 03 2010]
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MAPLE
| seq(sum(3*k-n, k=6..n), n=5..50); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 15 2008
a:=n->sum(denom (k/(k+3)), k=9..n): seq(a(n), n=8..53); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 31 2008
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MATHEMATICA
| i=-11; s=0; lst={}; Do[s+=n+i; If[s>=0, AppendTo[lst, s]], {n, 0, 6!, 1}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 29 2008]
Table[n (n+23)/2, {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 12, 25}, 50] (* From Harvey P. Dale, June 21 2011 *)
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CROSSREFS
| Cf. A000217, A056126.
Sequence in context: A186620 A042851 A041280 * A164577 A195143 A198274
Adjacent sequences: A132751 A132752 A132753 * A132755 A132756 A132757
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KEYWORD
| easy,nonn
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Aug 28 2007
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