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A118137
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Sum of decimal digits of two successive natural numbers.
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1
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1, 3, 5, 7, 9, 11, 13, 15, 17, 10, 3, 5, 7, 9, 11, 13, 15, 17, 19, 12, 5, 7, 9, 11, 13, 15, 17, 19, 21, 14, 7, 9, 11, 13, 15, 17, 19, 21, 23, 16, 9, 11, 13, 15, 17, 19, 21, 23, 25, 18, 11, 13, 15, 17, 19, 21, 23, 25, 27, 20, 13, 15, 17, 19, 21, 23, 25, 27, 29, 22, 15, 17, 19, 21, 23
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listen;
history;
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OFFSET
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0,2
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LINKS
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FORMULA
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MAPLE
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read("transforms") ;
digsum(n)+digsum(n+1) ;
# second Maple program:
a:= n-> add(i, i=convert(parse(cat(n, n+1)), base, 10)):
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MATHEMATICA
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a[n_] := Total@ Flatten@ IntegerDigits[{n, n+1}]; Array[a, 80, 0] (* Giovanni Resta, Sep 06 2019 *)
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PROG
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(PARI) a(n) = sumdigits(n) + sumdigits(n+1); \\ Michel Marcus, Sep 06 2019
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CROSSREFS
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KEYWORD
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base,easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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