login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A140706 A054525 * A014683; a(n) = Sum_{d|n} mu(d)*A014683(n/d). 1
1, 2, 3, 1, 5, 0, 7, 4, 5, 2, 11, 5, 13, 4, 6, 8, 17, 7, 19, 9, 10, 8, 23, 8, 19, 10, 18, 13, 29, 11, 31, 16, 18, 14, 22, 12, 37, 16, 22, 16, 41, 15, 43, 21, 25, 20, 47, 16, 41, 21, 30, 25, 53, 18, 38, 24, 34, 26, 59, 15, 61, 28, 37, 32, 46, 23, 67, 33, 42, 27, 71, 24, 73, 34, 41 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = n iff n is prime.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

FORMULA

Möbius transform of A014683: (1, 3, 4, 4, 6, 6, 8, 8, 9, 10, ...); where A014683(n) = n if n is not prime; but (n+1) if n is prime.

a(n) = Sum_{d|n} A008683(d)*A014683(n/d), where A008683 is Moebius mu function. - Antti Karttunen, Jul 28 2017

EXAMPLE

a(4) = 1 = (0, -1, 0, 1) dot (1, 3, 4, 4), where (0, -1, 0, 1) = row 4 of triangle A054525.

MAPLE

read("transforms") : A014683 := proc(n) if isprime(n) then 1+n; else n; fi; end: a014683 := [seq(A014683(n), n=1..150)] ; a140706 := MOBIUS(a014683) ; for i from 1 to nops(a140706) do printf("%d, ", op(i, a140706)) ; od: # R. J. Mathar, Jan 19 2009

MATHEMATICA

Table[Sum[MoebiusMu[d] (# + Boole@ PrimeQ@ #) &[n/d], {d, Divisors@ n}], {n, 75}] (* Michael De Vlieger, Jul 29 2017 *)

PROG

(PARI)

A014683(n) = (n+isprime(n));

A140706(n) = sumdiv(n, d, moebius(d)*A014683(n/d)); \\ Antti Karttunen, Jul 28 2017

(Python)

from sympy import isprime, mobius, divisors

def a014683(n): return n + isprime(n)

def a140706(n): return sum([mobius(d)*a014683(n/d) for d in divisors(n)])

print map(a140706, xrange(1, 101)) # Indranil Ghosh, Jul 29 2017

CROSSREFS

Cf. A008683, A014683, A054525.

Sequence in context: A201737 A080063 A187680 * A200068 A139764 A227643

Adjacent sequences:  A140703 A140704 A140705 * A140707 A140708 A140709

KEYWORD

nonn

AUTHOR

Gary W. Adamson, May 24 2008

EXTENSIONS

More terms from R. J. Mathar, Jan 19 2009

Second part added to the name by Antti Karttunen, Jul 28 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 17 11:51 EDT 2019. Contains 326057 sequences. (Running on oeis4.)