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A160944
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a(n)= n * digital sum(n-1) * digital sum(n+1)
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0
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0, 6, 24, 60, 120, 210, 336, 504, 72, 180, 33, 96, 195, 336, 525, 768, 1071, 1440, 342, 600, 168, 330, 552, 840, 1200, 1638, 2160, 2772, 870, 1320, 465, 768, 1155, 1632, 2205, 2880, 3663, 4560, 1716, 2400, 984, 1470, 2064, 2772, 3600, 4554, 5640, 6864
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listen;
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OFFSET
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1,2
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LINKS
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FORMULA
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EXAMPLE
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a(8)=8*ds(7)*ds(9)=8*7*9=504.
a(15)=15*ds(14)*ds(16)=15*5*7=525.
a(26)=26*ds(25)*ds(27)=26*7*9.
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MATHEMATICA
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Table[n Total[IntegerDigits[n-1]]Total[IntegerDigits[n+1]], {n, 50}] (* Harvey P. Dale, Nov 07 2021 *)
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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