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Search: id:A036659
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| A036659 |
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Product of n with sum of next n consecutive integers. |
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+0
5
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| 2, 14, 45, 104, 200, 342, 539, 800, 1134, 1550, 2057, 2664, 3380, 4214, 5175, 6272, 7514, 8910, 10469, 12200, 14112, 16214, 18515, 21024, 23750, 26702, 29889, 33320, 37004, 40950, 45167, 49664, 54450, 59534, 64925, 70632, 76664
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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a(n) = 2 +( 3*n*n +10*n +11 )*n/2. - frank.ellermann(AT)t-online.de, Mar 16 2002
a(n) = n^2(3n + 1)/2 - Ronnie B Kon (ronniekon(AT)yahoo.com), Jun 09 2006
a(n)=sum(sum(n+k, j=1..n),k=1..n), n>=1 - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 11 2007
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EXAMPLE
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n=3 -> 3*(4+5+6)=45
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MAPLE
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seq(add((n^2-k^2+(n+k)^2)/2, k=1..n), n=0..37); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 01 2006
a:=n->sum((n+j)*n, j=1..n): seq(a(n), n=1..37); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 29 2007
a:=n->sum(sum(n+k, j=1..n), k=1..n): seq(a(n), n=1..37); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 11 2007
a:=n->add(binomial(n, 2)+add(n, j=0..n), j=1..n):seq(a(n), n=1..40); # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 27 2008]
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CROSSREFS
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Cf. A036660.
Sequence in context: A075036 A091405 A085929 this_sequence A079937 A083102 A056080
Adjacent sequences: A036656 A036657 A036658 this_sequence A036660 A036661 A036662
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KEYWORD
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nonn
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AUTHOR
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G. L. Honaker, Jr. (honak3r(AT)gmail.com), Dec 15 1998
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