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Search: id:A075664
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| 1, 35, 405, 2584, 11375, 38961, 111475, 278720, 627669, 1300375, 2516921, 4604040, 8030035, 13446629, 21738375, 34080256, 52004105, 77474475, 112974589, 161603000
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OFFSET
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1,2
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FORMULA
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a(1)=1; a(n)=sum(i^s, {i, n(n-1)/2+1, n(n-1)/2+1+n})
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EXAMPLE
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s=3; a(1) = 1^s = 1; a(2) = 2^s + 3^s = 2^3+3^3 = 35; a(3) = 4^s + 5^s + 6^s = 64 + 125 + 216 = 405.
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MATHEMATICA
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i1 := n(n-1)/2+1; i2 := n(n-1)/2+n; s=3; Table[Sum[i^s, {i, i1, i2}], {n, 20}]
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CROSSREFS
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Cf. A006003 (s=1), A072474 (s=2), A075664 - A075670 (s=3-10), A075671 (s=n).
Sequence in context: A027803 A073567 A133458 this_sequence A133317 A105947 A107915
Adjacent sequences: A075661 A075662 A075663 this_sequence A075665 A075666 A075667
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Sep 24 2002
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