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A066804
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Sum of diagonal elements and those below it for a square matrix of integers, starting with 1.
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1
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1, 8, 34, 100, 235, 476, 868, 1464, 2325, 3520, 5126, 7228, 9919, 13300, 17480, 22576, 28713, 36024, 44650, 54740, 66451, 79948, 95404, 113000, 132925, 155376, 180558, 208684, 239975, 274660, 312976, 355168, 401489, 452200, 507570, 567876
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| T. A. Gulliver, Sequences from Arrays of Integers, Int. Math. Journal, Vol. 1, No. 4, pp. 323-332, 2002.
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 1..1000
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FORMULA
| a(n) = n*(n+1)*(2*n^2-n+2)/6
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PROG
| (MAGMA) [n*(n+1)*(2*n^2-n+2)/6: n in [1..30]]; // Vincenzo Librandi, May 22 2011
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CROSSREFS
| Sequence in context: A196143 A024847 A154516 * A033455 A172202 A053298
Adjacent sequences: A066801 A066802 A066803 * A066805 A066806 A066807
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KEYWORD
| easy,nonn
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AUTHOR
| Aaron Gulliver (agullive(AT)ece.uvic.ca), Jan 19 2002
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EXTENSIONS
| More terms from Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Mar 23 2002
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