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A085411 Total number of parts in all compositions of n into relatively prime parts. 2
1, 2, 7, 17, 47, 102, 255, 556, 1272, 2766, 6143, 13183, 28671, 61182, 131017, 277952, 589823, 1243800, 2621439, 5502191, 11534073, 24111102, 50331647, 104843732, 218103760, 452956158, 939522816, 1946095599, 4026531839, 8321365194 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..30.

FORMULA

Sum_{d|n} mu(n/d)*(d+1)*2^(d-2). G.f.: Sum_{k>=0} mu(k)*x^k*(1-x^k)/(1-2*x^k)^2.

Equals A054525 * A007318 * [1,2,3,...]. - Gary W. Adamson, Jun 11 2007

MATHEMATICA

f[n_] := Block[{d = Divisors[n]}, (Plus @@ (MoebiusMu[n/d]*(d + 1)*2^(d - 2)))]; Table[ f[n], {n, 1, 30}]

CROSSREFS

Cf. A001792, A000740.

Cf. A007318, A054525.

Sequence in context: A108479 A178441 A014742 * A180665 A275209 A007049

Adjacent sequences:  A085408 A085409 A085410 * A085412 A085413 A085414

KEYWORD

easy,nonn

AUTHOR

Vladeta Jovovic, Aug 13 2003

EXTENSIONS

More terms from Robert G. Wilson v, Aug 15 2003

STATUS

approved

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Last modified July 9 04:51 EDT 2020. Contains 335538 sequences. (Running on oeis4.)