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Search: id:A061077
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| A061077 |
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Sum of the products of the digits of the first n odd numbers. |
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+0
2
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| 1, 4, 9, 16, 25, 26, 29, 34, 41, 50, 52, 58, 68, 82, 100, 103, 112, 127, 148, 175, 179, 191, 211, 239, 275, 280, 295, 320, 355, 400, 406, 424, 454, 496, 550, 557, 578, 613, 662, 725, 733, 757, 797, 853, 925, 934, 961, 1006, 1069, 1150, 1150, 1150, 1150
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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The limit of the diagonals is A000712 (partitions into parts of two kinds). In particular, if 0<=m<=n, T(n(n+1)/2 + m, n) = A000712(m). These partitions in this range can be viewed as an equilateral right triangle of side n, with one partition appended on the top (at the left) and another appended on the right. - Frank Adams-Watters (FrankTAW(AT)Netscape.net), Jan 11 2006
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REFERENCES
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Amarnath Murthy, Smarandache friendly numbers and a few more sequences, Smarandache Notions Journal, Vol. 12, No. 1-2-3, Spring 2001.
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LINKS
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Matthew M. Conroy, Home page (listed instead of email address)
M. L. Perez et al., eds., Smarandache Notions Journal
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FORMULA
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a(n) = Sum_{k = 1..n} product of the digits of 2k+1.
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EXAMPLE
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a(7) = 1+3+5+7+9+1x1+1x3 = 29
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CROSSREFS
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Cf. A061076, A061078.
Sequence in context: A017668 A074373 A067115 this_sequence A086132 A010433 A126589
Adjacent sequences: A061074 A061075 A061076 this_sequence A061078 A061079 A061080
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KEYWORD
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nonn,base,easy
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 14 2001
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EXTENSIONS
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More terms from Matthew M. Conroy, Apr 16 2001
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