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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A305808 Dirichlet convolution of A032742 (the largest proper divisor of n) with itself. 3
1, 2, 2, 5, 2, 8, 2, 12, 7, 12, 2, 22, 2, 16, 12, 28, 2, 30, 2, 34, 16, 24, 2, 56, 11, 28, 24, 46, 2, 56, 2, 64, 24, 36, 16, 87, 2, 40, 28, 88, 2, 76, 2, 70, 46, 48, 2, 136, 15, 70, 36, 82, 2, 108, 24, 120, 40, 60, 2, 172, 2, 64, 62, 144, 28, 116, 2, 106, 48, 108, 2, 228, 2, 76, 70, 118, 24, 136, 2, 216, 81, 84, 2, 236, 36, 88, 60, 184, 2, 228, 28 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

FORMULA

a(n) = Sum_{d|n} A032742(n/d)*A032742(d).

PROG

(PARI)

A032742(n) = if(1==n, n, n/vecmin(factor(n)[, 1]));

A305808(n) = sumdiv(n, d, A032742(n/d)*A032742(d));

CROSSREFS

Cf. A032742, A300236, A300239, A305807.

Sequence in context: A030996 A293225 A305798 * A266662 A289078 A051612

Adjacent sequences:  A305805 A305806 A305807 * A305809 A305810 A305811

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jun 13 2018

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 May 25 22:17 EDT 2019. Contains 323576 sequences. (Running on oeis4.)