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A286315
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Number of representations of 10^n as sum of 8 triangular numbers.
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2
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8, 1332, 1030302, 1007141184, 1000302990372, 1000781337641904, 1000003970597090004, 1000751615026326041904, 1000203571630368710405892, 1004272191614371538730009600, 1000000970912716777250166728808, 1000834130646589459517111102258880
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OFFSET
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0,1
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COMMENTS
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a(n) is nearly 10^(3*n) because a(n) is almost (10^n+1)^3.
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LINKS
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FORMULA
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a(n) = Sum_{d|10^n+1, (10^n+1)/d == 1 mod 2} d^3.
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EXAMPLE
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a(0) = Sum_{d|2, 2/d == 1 mod 2} d^3 = 2^3 = 8.
a(1) = Sum_{d|11, 11/d == 1 mod 2} d^3 = 11^3 + 1^3 = 1332.
a(2) = Sum_{d|101, 101/d == 1 mod 2} d^3 = 101^3 + 1^3 = 1030302.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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