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A338827
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For any number with decimal representation (d(1), d(2), ..., d(k)), the decimal representation of a(n) is (abs(d(1)-d(k)), abs(d(2)-d(k-1)), ..., abs(d(k)-d(1))).
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2
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 11, 22, 33, 44, 55, 66, 77, 88, 22, 11, 0, 11, 22, 33, 44, 55, 66, 77, 33, 22, 11, 0, 11, 22, 33, 44, 55, 66, 44, 33, 22, 11, 0, 11, 22, 33, 44, 55, 55, 44, 33, 22, 11, 0, 11, 22, 33, 44, 66, 55, 44, 33, 22, 11, 0, 11, 22
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OFFSET
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0,11
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COMMENTS
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Leading zeros are ignored.
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LINKS
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FORMULA
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a(n) = 0 iff n is a palindrome (A002113).
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EXAMPLE
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For n = 1021:
- abs(1-1) = 0,
- abs(0-2) = 2,
- abs(2-0) = 2,
- abs(1-1) = 0,
- so a(1021) = 220.
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MAPLE
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a:= n-> (l-> (h-> add(h[j]*10^(j-1), j=1..nops(h)))([seq(
abs(l[i]-l[-i]), i=1..nops(l))]))(convert(n, base, 10)):
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PROG
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(PARI) a(n, base=10) = my (d=digits(n, base)); fromdigits(abs(d-Vecrev(d)), base)
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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