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A061076
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a(n) is the sum of the products of the digits of all the numbers from 1 to n.
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4
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1, 3, 6, 10, 15, 21, 28, 36, 45, 45, 46, 48, 51, 55, 60, 66, 73, 81, 90, 90, 92, 96, 102, 110, 120, 132, 146, 162, 180, 180, 183, 189, 198, 210, 225, 243, 264, 288, 315, 315, 319, 327, 339, 355, 375, 399, 427, 459, 495, 495, 500, 510, 525, 545, 570, 600, 635
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| What is the asymptotic behavior of this sequence? a(n) = a(n+1) for almost all n. A weak upper bound: a(n) << n^1.91. [Charles R Greathouse IV, Jan 13 2012]
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REFERENCES
| 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
| Matthew M. Conroy, Home page (listed instead of email address)
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FORMULA
| a(n) = Sum_{k = 1..n} product of the digits of k.
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EXAMPLE
| a(9)=a(10)=1+2+3+4+5+6+7+8+9+1x0=1+2+3+4+5+6+7+8+9=45.
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CROSSREFS
| Sequence in context: A107082 A187845 A130488 * A054632 A109453 A037123
Adjacent sequences: A061073 A061074 A061075 * A061077 A061078 A061079
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KEYWORD
| nonn,base,easy
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 14 2001
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EXTENSIONS
| Corrected and extended by Matthew M. Conroy, Apr 16 2001
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