login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A318505 Sum of divisors of n, up to, but not including the second largest of them A032742(n); a(1) = 0 by convention. 9
0, 0, 0, 1, 0, 3, 0, 3, 1, 3, 0, 10, 0, 3, 4, 7, 0, 12, 0, 12, 4, 3, 0, 24, 1, 3, 4, 14, 0, 27, 0, 15, 4, 3, 6, 37, 0, 3, 4, 30, 0, 33, 0, 18, 18, 3, 0, 52, 1, 18, 4, 20, 0, 39, 6, 36, 4, 3, 0, 78, 0, 3, 20, 31, 6, 45, 0, 24, 4, 39, 0, 87, 0, 3, 24, 26, 8, 51, 0, 66, 13, 3, 0, 98, 6, 3, 4, 48, 0, 99, 8, 30, 4, 3, 6, 108, 0, 24, 24, 67, 0, 63, 0, 54, 52 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

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

Index entries for sequences related to sums of divisors

FORMULA

a(1) = 0; for n > 1, a(n) = A001065(n)-A032742(n).

PROG

(PARI)

A001065(n) = (sigma(n)-n);

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

A318505(n) = if(1==n, 0, A001065(n)-A032742(n));

A318505(n) = sumdiv(n, d, (d<A032742(n))*d); \\ Alternatively.

CROSSREFS

Cf. A001065, A032742, A318504, A318506, A318507, A318508.

Sequence in context: A300904 A307807 A318504 * A237595 A322575 A166445

Adjacent sequences:  A318502 A318503 A318504 * A318506 A318507 A318508

KEYWORD

nonn

AUTHOR

Antti Karttunen, Aug 27 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 June 6 11:14 EDT 2020. Contains 334827 sequences. (Running on oeis4.)