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A131812
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Sum of all n-digit Woodall numbers.
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0
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8, 86, 1437, 6654, 81917, 827389, 17956860, 157286397, 1434451965, 12884901885, 114353504253, 1005022347261, 8761733283837, 166026255794172, 1337006139375613, 11434920928870397, 97390341941886973, 1799188051134513148, 14231374822490767357, 119903836479112085501
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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EXAMPLE
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Sum of all 1-digit Woodall numbers is 1 + 7 = 8.
Sum of all 2-digit Woodall numbers is 23 + 63 = 86.
Sum of all 3-digit Woodall numbers is 159 + 383 + 895 = 1437.
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MATHEMATICA
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digNum[n_] := Length @ IntegerDigits[n]; woodall[n_] := n * 2^n - 1; digCount = 0; sum = 0; cumsum = {}; Do[w = woodall[n]; If[digNum[w] > digCount, digCount++; AppendTo[cumsum, sum]]; sum += w, {n, 1, 65}]; Differences[cumsum] (* Amiram Eldar, Nov 30 2019 *)
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CROSSREFS
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KEYWORD
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nonn,base,less
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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