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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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1
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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
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OFFSET
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0,2
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COMMENTS
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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. - Franklin T. Adams-Watters, 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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Table of n, a(n) for n=0..52.
Matthew M. Conroy, Home page (listed instead of email address)
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FORMULA
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a(n) = Sum_{k = 1..n} product of the digits of 2k+1.\
a(5*10^n) = 25*46^n, so a(n) is roughly kn^1.662... where the exponent is log 46/log 10. - Charles R Greathouse IV, Sep 20 2012
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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: A225004 A074373 A067115 * A086132 A010433 A175592
Adjacent sequences: A061074 A061075 A061076 * 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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STATUS
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approved
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