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A062791 Moebius transform of central binomial coefficients. 1
1, 1, 2, 4, 9, 16, 34, 64, 123, 241, 461, 900, 1715, 3396, 6423, 12800, 24309, 48477, 92377, 184500, 352679, 704969, 1352077, 2703168, 5200290, 10398883, 20058174, 40113164, 77558759, 155110827, 300540194, 601067520, 1166802646, 2333581909, 4537567606 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = Sum_{d|n} A001405(n/d)*mu(d).

EXAMPLE

n=7, C[7,3]=35, A001405[7/d]={C[7,3],C[1,0]}={35,1}, mu[d]={1,-1}, the sum is a(7)=35-1=34.

MAPLE

with(numtheory):

a:= n-> add(binomial(d, iquo(d, 2))*mobius(n/d), d=divisors(n)):

seq(a(n), n=1..40);  # Alois P. Heinz, Jul 09 2017

CROSSREFS

Cf. A001405.

Sequence in context: A302831 A091437 A131337 * A203320 A005980 A128093

Adjacent sequences:  A062788 A062789 A062790 * A062792 A062793 A062794

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 19 2001

EXTENSIONS

Offset corrected by Eric Rowland, Jul 09 2017

STATUS

approved

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Last modified July 27 13:36 EDT 2021. Contains 346306 sequences. (Running on oeis4.)