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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A094701 Least linear combination of phi(n) and sigma(n). 1
1, 2, 2, 2, 2, 1, 2, 2, 3, 3, 2, 3, 2, 4, 5, 2, 2, 3, 2, 4, 7, 4, 2, 2, 5, 4, 3, 1, 2, 5, 2, 2, 9, 4, 18, 3, 2, 4, 9, 4, 2, 7, 2, 6, 3, 4, 2, 3, 7, 5, 9, 5, 2, 3, 7, 3, 9, 4, 2, 5, 2, 4, 7, 2, 11, 7, 2, 9, 9, 10, 2, 3, 2, 4, 12, 4, 10, 7, 2, 5, 3, 4, 2, 3, 13, 4, 9, 4, 2, 5, 9, 9, 9, 4, 19, 3, 2, 7, 5, 5, 2, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) is least sum of coefficients of the 2 functions such that the form is a multiple of n. a(n) is a generalization of multiperfect number.

LINKS

Table of n, a(n) for n=1..102.

FORMULA

a(multiperfect) = 1. a(prime) = 2 as 1*phi(prime) + 1*sigma(prime) and 1+1 = 2. For primes > 5, a(2*prime) = 4.

EXAMPLE

a(6) = 1 as 1*sigma(6) is a multiple of 6.

a(14) = 4 as 3*phi(14) + 1*sigma(14) = 3*6 + 24 = 3*14, where 3+1 = 4.

CROSSREFS

Cf. A000010, A000203, A000396, A005820, A027687, A046060, A046061.

Sequence in context: A318882 A055020 A052435 * A210452 A240301 A289641

Adjacent sequences:  A094698 A094699 A094700 * A094702 A094703 A094704

KEYWORD

nonn

AUTHOR

Walter Nissen, May 20 2004

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 24 16:16 EDT 2019. Contains 326295 sequences. (Running on oeis4.)