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Search: id:A093353
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| A093353 |
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(n + n mod 2) * (n + 1) / 2. |
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+0
4
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| 2, 3, 8, 10, 18, 21, 32, 36, 50, 55, 72, 78, 98, 105, 128, 136, 162, 171, 200, 210, 242, 253, 288, 300, 338, 351, 392, 406, 450, 465, 512, 528, 578, 595, 648, 666, 722, 741, 800, 820, 882, 903, 968, 990, 1058, 1081, 1152, 1176, 1250, 1275, 1352, 1378, 1458
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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a(2*n) = a(2*n-1) + n = A014105(n);
a(2*n+1) = a(2*n) + 3*n + 2 = A001105(n+1).
Partial sums of A014682(n+1). - Paul Barry (pbarry(AT)wit.ie), Mar 31 2008
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FORMULA
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G.f.: [2+x+x^2]/[(1-x)^3(1+x)^2].
a(n)=(n+1)(2n+1-(-1)^n)/4; - Paul Barry (pbarry(AT)wit.ie), Mar 31 2008
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MAPLE
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a:=n->sum(n, j=1..n/2): seq(a(n), n=2..55); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 30 2007
a:=n->add(add(1+(-1)^j, j=1..n), j=1..n):seq(a(n)/2, n=2..52); # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 13 2008]
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CROSSREFS
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Cf. A000217.
Sequence in context: A132327 A100317 A060697 this_sequence A083799 A098844 A034437
Adjacent sequences: A093350 A093351 A093352 this_sequence A093354 A093355 A093356
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 27 2004
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