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A287894
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Sum of the digit sums of the n-th powers of the first n positive integers.
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2
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1, 5, 18, 30, 33, 94, 136, 186, 225, 268, 348, 413, 502, 682, 792, 938, 1098, 1254, 1441, 1529, 1647, 1905, 2148, 2392, 2674, 2961, 3150, 3493, 3804, 4007, 4417, 4636, 5103, 5576, 5850, 6234, 6769, 7175, 7659, 7713, 8538, 8848, 9406, 9957, 10332, 11218, 11877
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OFFSET
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1,2
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COMMENTS
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The sequence is not increasing: a(100) < a(99). - Robert Israel, Jun 30 2017
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LINKS
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FORMULA
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a(n) = Sum_{k=1..n} digsum(k^n), n >= 1.
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EXAMPLE
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n=1: 1: 1;
n=2: 1,4: 1+4=5;
n=3: 1,8,27: 1+8+9=18;
n=4: 1,16,81,256: 1+7+9+13=30.
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MAPLE
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ds:= n -> convert(convert(n, base, 10), `+`):
f:= n -> add(ds(k^n), k=1..n):
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MATHEMATICA
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a[n_] := Sum[ Total@ IntegerDigits[k^n], {k, n}]; Array[a, 50] (* Giovanni Resta, Jun 07 2017 *)
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PROG
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(PARI) a(n) = sum(k=1, n, sumdigits(k^n)); \\ Michel Marcus, Jun 06 2017
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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