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A062790 Moebius transform of cototient function. +0
1
0, 1, 1, 1, 1, 2, 1, 2, 2, 4, 1, 3, 1, 6, 5, 4, 1, 6, 1, 5, 7, 10, 1, 6, 4, 12, 6, 7, 1, 8, 1, 8, 11, 16, 9, 8, 1, 18, 13, 10, 1, 12, 1, 11, 12, 22, 1, 12, 6, 20, 17, 13, 1, 18, 13, 14, 19, 28, 1, 13, 1, 30, 16, 16, 15, 20, 1, 17, 23, 24, 1, 16, 1, 36, 24, 19, 15, 24, 1, 20, 18, 40, 1, 19 (list; graph; listen)
OFFSET

1,6

COMMENT

Inverse Moebius transform of A051953 is A001065, the sum of proper divisors of n.

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,2000

FORMULA

a(n)=Sum{f[n/d]*mu[d]}, where d divides n and f[x]=x-Phi[x]=A051953(x).

EXAMPLE

n=255,divisors={1,3,5,25,17,51,85,255}, A051953[255/d]={127,21,19,1,7,1,1,0},mu[d]={1,-1,-1,1,-1,1,1,-1}, the sum is a(255)=127-21-19+1-7+1+1+0=130-47=83.

PROGRAM

(PARI) { for (n=1, 2000, d=divisors(n); a=sum(k=1, length(d), (n/d[k] - eulerphi(n/d[k])) * moebius(d[k])); write("b062790.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 11 2009]

CROSSREFS

A051953, A001065.

Sequence in context: A151678 A151681 A131097 this_sequence A046640 A049823 A143775

Adjacent sequences: A062787 A062788 A062789 this_sequence A062791 A062792 A062793

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Jul 19 2001

EXTENSIONS

OFFSET changed from 0,6 to 1,6 by Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 11 2009

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Last modified December 17 23:40 EST 2009. Contains 171025 sequences.


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