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A129468 Unitary abundance of n. 8
-1, -1, -2, -3, -4, 0, -6, -7, -8, -2, -10, -4, -12, -4, -6, -15, -16, -6, -18, -10, -10, -8, -22, -12, -24, -10, -26, -16, -28, 12, -30, -31, -18, -14, -22, -22, -36, -16, -22, -26, -40, 12, -42, -28, -30, -20, -46, -28, -48, -22, -30, -34, -52, -24 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
The values of n which generate negative elements of this sequence are in A129487, the values of n which generate the zeros of this sequence are in A002827 and the values of n which generate positive elements of this sequence are in A034683
LINKS
Eric Weisstein's World of Mathematics, Unitary Divisor.
FORMULA
a(n)=A034460(n)-n=A034448(n)-2n.
EXAMPLE
As the unitary divisors of 12 are 1, 3, 4 and 12, which sum to 20, then a(12)=20-2x12=-4
MAPLE
A129468 := proc(n)
A034448(n)-2*n ;
end proc:
seq(A129468(n), n=1..40) ; # R. J. Mathar, Nov 10 2014
MATHEMATICA
UnitaryDivisors[n_Integer?Positive]:=Select[Divisors[n], GCD[ #, n/# ]==1&]; sstar[n_]:=Plus@@UnitaryDivisors[n]-n; sstar[ # ]-#&/@Range[40]
CROSSREFS
Sequence in context: A065332 A265515 A336564 * A236846 A236847 A091703
KEYWORD
easy,sign
AUTHOR
Ant King, Apr 17 2007
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)